Chem Semester 1 Review

A compound has 15.39 g of gold for every 2.77 g of chlorine. Simplified, there is ____ g of gold for every 1 g of chlorine. (Round to two decimal places)

5.56

Why do nutrients need to be added to the soil?

Different areas have different concentrations of nutrients. Crops also deplete certain nutrients each year.

How is most scientific research carried out today?

Mostly at private companies or Universities.

Which compound has the lowest ratio of nitrogen to oxygen?

N2O5

How was the nitroglycerin made more stable?

Nitroglycerin was mixed with Silica to stabilize it and form a solid material

Who owned the gold mines during ancient Egyptian and Roman Civilizations?

No specific group or individual, they were a property of the state

Is it always easy to classify research as pure or applied? Explain your answer.

No, sometimes it could start off as pure then end up as applied (line isn't always distinct)

Salt is a pure compound. (T/F)

True

The melting point, boiling point, and freezing point of a substance can be determined easily and exactly and are known as the physical properties. (T/F)

True

Stan is researching a new insecticide that will be less toxic to birds and mammals that may come in contact with it.

applied chemistry

What was the basic shortcoming of the Greek philosophers approach to studying the material world?

asking questions, discussing/debating them

John Dalton

atomic theory, atoms can combine to form compounds

Democritus believed that all natural substances were made of _____.

atoms

What is all matter made of?

atoms

According to the atomists, the entire physical world was made of:

atoms and void

In carbonated water, when carbon dioxide bubbles are thoroughly mixed into the water, they become invisible. What type of mixture is carbonated water?

solution

acceleration (a)

speed/time (m/s^2)

Law

statement that is always true without explanation

Substances can exist in three _____ / _____

states, phases

potential energy

stored energy

Elixir of Life

substance believed to give immortality to the person who possessed it

Lemonade is a murky yellow color. If you leave it sitting for a few minutes, you might need to stir it again before you drink it. What type of mixture is lemonade?

suspension

Define "deductive reasoning"

taking the general principle and drawing a specific conclusion

chemical property

the ability of a substance to undergo a specific chemical change

energy

the ability to do work

analytical chemistry

the area of study that focuses on the composition of matter (measuring mercury in seawater)

What two things need to be studied to develop a new drug?

the chemistry of the disease and how the drug may affect the body

precision

the exactness of a measurement

How do hand warmers work?

the iron fillings inside the package react with the air to release thermal energy

In a distillation process, which liquid component of the mixture passes through the condenser first?

the one with the lower boiling point

chemical reaction

the process by which one or more substances change to produce one or more different substances

chromatography

the separation of a mixture by passing it in solution or suspension or as a vapor through a medium in which the components move at different rates.

organic chemistry

the study of carbon compounds (synthesizing new carbon compounds)

biochemistry

the study of substances and processes occurring in living things (studying enzymes in cells)

physical chemistry

the study of the properties and changes of matter and their relation to energy (making new compounds) (measuring the electrical properties of solutions)

Macroscopic world

the things we can see, touch, and measure directly

How do batteries create energy?

there is a release of electrons that flows through the circuit providing a current of electricity

Is it easy to classify research as pure or applied?

there is not always a clear line between the two (question can fall under pure research and lead to advancement of knowledge)

What did Erwin Schrodinger and Werner Heisenberg contribute to the atomic theory?

they created the quantum model and found that it is impossible to know the exact speech and location of electrons giving the model a cloud shape

pure research

to gain knowledge for the sake of knowledge itself

Air has its components spread evenly, so it is considered a homogenous mixture. (T/F)

true

Because the length, width and height of a cube are both extensive properties, the volume of the cube is also an extensive property. (T/F)

true

Compounds have fixed compositions whereas mixtures vary in composition. (T/F)

true

Properties of matter such as density, odor, color, and melting point do not vary with the amount of matter. Such properties are called intensive properties. (T/F)

true

T or F Every molecule of carbon dioxide consists of 1 atom(s) of carbon and 2 atom(s) of oxygen.

true

T or F The law of definite proportions is only applicable when the elements which are reacting together form the same product.

true

T or F According to Democritus, changes occur if atoms in an object are recombined or reconnected in different ways.

true

T or F Ancient Greek philosophers had many ideas about the natural world and how it worked.

true

T or F Atoms, according to Democritus, always existed and are unchangeable and indestructible.

true

T or F Democritus believed that atoms were always in motion.

true

T or F Democritus proposed the theory of atomism.

true

T or F Democritus stated that different atoms differ in magnitude.

true

T or F Democritus suggested that the complete universe is made up of minute particles which are indivisible.

true

T or F Protons have much more mass than electrons do.

true

T or F The ancient Greek philosophers spend their time by debate and discussion.

true

T or F The idea of the atom was the major contribution of Democritus made to the thinking of his day

true

T or F Whenever the same two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.

true

The composition of a mixture is varied by altering the proportions of its constituents. (T/F)

true

Water is a homogeneous mixture which contains dissolved gases and minerals. (T/F)

true

evaporation

used to separate homogeneous mixtures when there is more than one dissolved solids

Give an example of applied research.

vaccination development for a virus

heterogeneous mixture

varies in composition throughout the mixture (rocks)

Which property of a glass of water is an example of an extensive physical property?

volume of water

Examples of extensive property are ____ and ____

volume, mass

Three things crops need for good growth

water, nutrients from soil and protection from insects

melting/boiling point

way to identify a compound

Which property of a glass of juice is an example of an extensive physical property?

weight

How does burning gasoline power a car?

when petroleum products are ignite, it creates a increase in gas and volume which provides power by moving pistons in the internal combustion engine

power = ________ / ________

work/time

Two ways chemists helped with issues related to lead contamination

developed methods to remove lead from the body, create new gasoline products with good fuel efficiency

Why nutrients need to be added to soil?

different areas have different levels of soil, crops also get rid of certain nutrients each year

JJ Thompson

discovered electrons, plum pudding model

Ernest Rutherford

discovered the positive nucleus, atom is mostly made of empty space, planetary model

In which of the following ways would one separate a miscible solution of benzene and chloroform?

distillation

What separation technique separates liquids using differences in their boiling points?

distillation

Which of the following is a viable method of separating gasoline from crude oil?

distillation

example of pure research:

early philosophers debated and discussed theories without practical application

Solar cells convert chemical energy to ______ energy

electrical

Where are liquid crystals used?

electronic displays (watches, calculators)

Heisenberg and Schrodinger

electrons are in orbitals, don't know where the electrons are located exactly (can't know their exact location)

Niels Bohr

electrons orbit the nucleus based on energy levels

Substances may either be _____ or ________

elements, compounds

Besides matter, all chemical reactions require _______ in order for the reaction to occur.

energy

exothermic reaction

energy is released when bonds form in products then is used to break bonds in reactants

endothermic reaction

energy is used to break bonds in reactants then is released when bonds form in products

kinectic energy

energy of motion (KE = 1/2mv^2)

For any chemical process in an isolated system in which all reactants are converted to products, the original mass of reactants must be _____ the final mass of products.

equal to

In _______, solids can be separated from liquids by heating the liquid and removing it.

evaporation

What separation technique is used to separate a dissolved solid from the liquid in which it is dissolved?

evaporation

A property that depends on the amount of matter (mass or volume) in a sample is an ______ property

extensive

A homogeneous mixture is a composition of two or more impure substances in a definite proportion, displaying non-uniform characteristics. (T/F)

false

A solution of salt and water is a heterogeneous mixture. (T/F)

false

Because mass and volume are both extensive properties, density (mass/volume) is also an extensive property. (T/F)

false

Because the amount (n) and the mass (m) of a substance are both extensive properties, the molar mass (molar mass = m/n) of the substance is also an extensive property. (T/F)

false

Because the amount of solute and the volume of solution are both extensive properties, concentration of a solution (amount of solute/volume) is also an extensive property. (T/F)

false

Because the more water you boil the more time it will take (other conditions are constant) the boiling point of water is an extensive physical property. (T/F)

false

Boiling point is not an intensive physical property. (T/F)

false

Chemical properties of matter are categorized as either intensive or extensive. (T/F)

false

Gases form heterogeneous mixtures with each other regardless of the identities or relative properties of the component gases. (T/F)

false

Mixtures are considered to be pure substances. (T/F)

false

Mixtures can only be separated by a chemical change. (T/F)

false

Solutions are heterogeneous since the ratio of solute to solvent does not remain the same throughout the solution. (T/F)

false

T or F A chemical compound is always found to be made up of the same elements combined together in different proportions by mass.

false

T or F According to Democritus, atoms are solid particles which are destructible.

false

T or F The neutron has a charge.

false

T or F An extension of Democritus theory states that there were different varieties of atomos with same shapes, sizes and masses.

false

T or F Atoms are the smallest particles in the universe.

false

T or F Greek philosophers accepted most of the discoveries on the basis of experiments they performed.

false

T or F In carbon dioxide, 12 grams of carbon combines with 16 grams of oxygen.

false

T or F Science and experimentation were active pursuits in ancient Greece.

false

T or F The theory of Democritus and Leucippus held that everything is composed of 'atoms', which are geometrically indivisible.

false

While carrying out filtration of a solution, the substance which remains on the filter paper is the water-soluble part. (T/F)

false

Separation by physical size is ______.

filteration

Democratis

first to discover the atom (found that it was uncuttable and that it was the smallest form)

What is not a physical property of matter?

flammability, reactivity with oxygen, ability to react chemically

work = _________ * __________

force * distance

energy (E)

force * length (J)

What did Democritus contribute to the atomic theory?

found matter can be cut into smaller pieces known as atoms (uncuttable)

Where was lead found in products?

gas, paint, plumbing pipes

Define "inductive reasoning"

getting a collection of specific examples and drawing a general conclusion

What chemical are diabetics unable to produce?

glucose

homogeneous mixture

has the same composition throughout the mixture (salt water), uniform composition

What did Niels Bohr contribute to the atomic theory?

he created Bohr's Model and found the atom is smaller than we thought with electrons in distinct orbitals around the nucleus

What did JJ Thomson contribute to the atomic theory?

he created the plum pudding model and discovered electrons

What did Ernest Rutherford contribute to the atomic theory?

he discovered most of an atom is empty space and all atoms have a positively charged nucleus in the center

A _______ mixture is a mixture in which the composition is uniform throughout the mixture.

homogeneous

Sugar dissolves completely in water to form a solution. This solution is a _____.

homogeneous mixture

law

how

accuracy

how close a measurement is to the true value

What are synthetic polymers made from?

hydrocarbons in petroleum products

Theory

hypothesis or guess confirmed repeatedly (offers description as to why something happened)

According to Aristotle, how long could one divide a grain of sand?

indefinitely

mass is _______ of location

independent

What word does the ancient greek word "atomos" roughly translate to?

indivisible

Louis is investigating a new way to isolate nickel from various nickel-containing rocks and sediment. Identify the type of chemistry.

inorganic

(identify type of chemistry) making new compounds for energy processes

inorganic chemistry

A property of matter that depends only on the type of matter in a sample and not on the amount is _____

intensive

Density is an _____ property

intensive

Melting point is an _____ physical property.

intensive

How do pesticides work?

interfere with the biochemical process of the pest

__________ is the SI base unit of energy

joule (J)

What is temperature's SI base unit?

kelvin (K)

What is mass's SI base unit?

kilogram (kg)

What law states that elements can combine with one another in different mass ratios?

law of multiple proportions

Which property of a strip of copper wire is an example of an extensive physical property?

length of strip

volume (V)

length x width x height (m^3)

speed, velocity (V)

length/time (m/s)

force = ________ * ________

mass * acceleration

acceleration = ______ /_______

mass / second ^2

force (F)

mass x acceleration (N)

density

mass/volume

density (D)

mass/volume (kg/m^3)

Superconductor

material able to conduct electricity with 100% efficiency

substance

matter that has a uniform and definite composition

inorganic chemistry

measuring the electrical properties of solutions (making new compounds for energy purposes)

What is length's SI base unit?

meter (m)

The two worlds of the chemist are the macroscopic and ________ world.

microscopic

Aspirin pills contain aspirin and some ingredients that don't have medicinal function, such as corn starch and cellulose. Based on this, would you classify an aspirin pill as a mixture or a pure substance?

mixture

What is the amount of substance SI base unit?

mole (mol)

What best describes gas particles?

moving randomly, colliding with each other, high kinetic energy

The radius of an atom is closest in size to a _________ .

nanometer

Will the composition of water vary depending on its source? (Yes or No)

no

liquid

no definite shape, definite volume, particles move freely

gas

no definite shape, no definite volume, particles move freely and are not attracted to each other

Give two examples of discoveries chemists have found to help surgical patients

non-reactive blood vessels used during heart and other surgeries, dissolvable materials that don't need to be removed

What do all atoms of the same element have in common?

number of protons

(identify type of chemistry) synthesizing new carbon compounds

organic chemistry

example of applied research:

petroleum companies finding better ways to power vehicles, create better lubricants to prevent engine wear and lower pollution

When oil and water are mixed, two separate layers form. Each layer is called a(n) _____.

phase

Color and shape are both examples of _____ properties

physical

(identify type of chemistry) measuring electrical properties of solutions

physical chemistry

A characteristic of a substance that can be observed or measured without changing the identity of the substance

physical property

product

present at the end of the chemical reaction, what is produced because of the reaction

reactant

present at the start of the chemical reaction

Who owned the gold mines during the ancient Egyptian and Roman civilizations?

property of the state not an individual person

A neutral atom has equal numbers of ______and electrons.

protons

_____ are attracted to negatively charged particles and repelled from positively charged particles.

protons

What is contained in the nucleus of an atom?

protons and neutrons

Tina is researching the rates of reactions of various compounds to see how the reaction rate depends on the solubility of the compound.

pure chemistry

applied research

research done to solve a specific problem or make advancements

How is research usually funded?

research groups raise money and government groups provide money

How do scientists share their findings?

scientific journals

What is time's SI base unit?

second (s)

chemical formula

shows the elements in the compound and the ratio of atoms

Nitroglycerin can be made more stable by mixing with ______.

silica

The color of most metals is ______.

silver

element

simplest form of matter that has a unique set of properties, can't be broken down

How does the mass of the neutron compare to the mass of the proton?

slightly greater

Microscopic world

small particles that make up all matter

Give two examples of chemistry in your everyday life

soap and cooking

states of matter

solid, liquid, gas

How much of the water used in farming is provided by irrigation?

18%

How much of water used in farming is provided by irrigation?

18%

In carbon dioxide, there is always 2.66 g of oxygen for every 1 g of carbon. How many grams of oxygen are in a 25.62 gram sample of carbon dioxide?

18.62

How many grams of carbon would be present in carbon monoxide that contains 2.66 grams of oxygen?

2

How many valence electrons does beryllium have?

2

compounds

2 or more elements chemically combined

synthesis reaction

2 or more reactants combine to synthesize a single product

In one compound of lead and sulfur, there are 6.46 g of lead for every gram of sulfur. In another, there are 3.23 g of lead for every gram of sulfur. What is the simple whole number ratio for the masses of lead that can make compounds with sulfur? (Write your answer ratio format. e.g: 5:2)

2 to 1

All samples of a specific substance have the same chemical composition. (T/F)

True

Who was the most influential philosopher when it came to the subject of the composition of the natural world?

Aristotle

Aspirin is a mixture of different compounds. (T/F)

True

Brittleness, malleability, ductility, and viscosity fall into the category of physical properties of matter. (T/F)

True

phase

any part of a sample with uniform composition and properties

Liquids are _____ than gases

denser

weight is _________ of location

dependent

hardness

determines how an element might be used

Water is 11.19% hydrogen and 88.81% oxygen by mass. Lake Superior contains about 1.2×1016 kg of water. What mass of hydrogen is contained in Lake Superior?

1.3 x10^15

List two areas where chemistry has helped surgical patients

-Artificial skin -sterile materials -stents

What contributions to modern chemistry were made by the alchemists?

-Periodic Table -inks -dyes -paints -leather tanning -ceramics -glass

How is research usually supported?

-grants -funds from colleges and universities (some of the studies take place there)

Why is gold considered to be valuable?

-it doesn't get destroyed or damaged -very rare -used as money

List two ways chemists help with issues related to lead contamination.

-measure the amount of lead in the soil, paint, plumbing, blood -and it is measured in more materials Chemists find ways to create efficient products that do not use lead. Chemists also study the impact the lead has had on humans and how to help.

List three things crops need for good growth.

-nutrients -water -protection from insects (predators)

pico (p)

0.000000000001 (10^-12)

nano (n)

0.000000001 (10^-9)

micro

0.000001 (10^-6)

milli (m)

0.001 (10^-3)

centi (c)

0.01 (10^-2)

deci (d)

0.1 (10^-1)

The mass ratio of H to O in water (H2O) is 1:8. What is the mass ratio of H to O in hydrogen peroxide (H2O2)?

1 to 16

n glucose (C6H12O6), the simplified ratio of C atoms to H atoms is

1 to 2

kilo (k)

1,000 (10^3)

mega (M)

1,000,000 (10^6)

giga (G)

1,000,000,000 (10^9)

A reaction of heating potassium permanganate produces potassium manganate, manganese dioxide and oxygen gas. Heat 15.8 g potassium permanganate until no more oxygen gas is given off. The remaining material has a mass of 14.2 g. What mass of oxygen gas was produced in the reaction? ___ g

1.6

In the compound nickel(II) sulfide, there is always 58.7 g of nickel for every 32.1 g of sulfur. What is the simplified ratio of nickel to sulfur?

1.83 to 1

SI system is based off of ______________?

10

deka (da)

10 (10^1)

A reaction of 12.640 g of copper oxide with 0.316 g hydrogen produces 2.844 g of water and X g of copper. X = ___ g

10.112

hecto (h)

100 (10^2)

What is a superconductor?

100% efficient conductor

1 kilometer = _______ meters

1000

When heated, calcium hydroxide and ammonium chloride react to produce ammonia gas, water vapor, and solid calcium chloride. Suppose 5.00g of calcium hydroxide and 10.00g of ammonium chloride are mixed in a test tube and heated until no more ammonia is given off. The remaining material in the test tube has a mass of 1.27 g. What is the total mass of ammonia and water vapor produced? ___ g

13.73

According to the law of conservation of mass, if an atom of element A has a mass of 2 units, while an atom of element B has a mass of 5 units, what would be the mass of the compound A3B2?

16 units

2.56 g of hydrogen reacts completely with 20.32 g of oxygen to form X g of water. X = ___g

22.88

There are two compounds of gold and chlorine. In one compound, there is 15.39 g of gold for every 2.77 g of chlorine. In the other compound, there is 7.74 g of gold for every 4.18 g of chlorine.Find the ratio of masses of gold in the two compounds.

3 to 1

Two compounds of phosphorus and fluorine have the following mass ratios.Compound 1: 10.14 g fluorine for every 3.38 g phosphorusCompound 2: 8.42 g fluorine for every 4.21 g phosphorusFind the whole number ratio of masses of fluorine in compound 1 to compound 2.

3 to 2

A reaction of 22.85 g of sodium hydroxide with 20.82 g of hydrogen chloride produces 10.29 g of water and X g of sodium chloride. X = ___ g

33.38

A neutral atom has 37 electrons. How many protons does the atom have?

37

The molecular formula for ethane is C2H6. What is the carbon:hydrogen mass ratio for ethane?

4 to 1

A reaction of heating calcium carbonate produces calcium oxide and carbon dioxide gas. Heat 10.0 g calcium carbonate until no more carbon dioxide gas is given off. The remaining material has a mass of 5.6 g. What mass of carbon dioxide gas was produced in the reaction? ___ g

4.4

What fraction of crops are grown using irrigation?

40%

A reaction between ammonia gas and chlorine gas produces ammonium chloride and nitrogen gas. A reaction of 17.0 g of ammonia with 26.6 g of chlorine gas gives off 3.50 g of nitrogen. What mass of ammonium chloride is formed in the reaction? ___ g

40.1

Calcium carbonate, CaCO3, decomposes when heated to calcium oxide (CaO) and carbon dioxide (CO2). If 100 g of calcium carbonate is allowed to decompose, 56 g of calcium oxide is produced. What mass of carbon dioxide is produced by the decomposition?

44

Serotonin (C10H12N2O) is a neurotransmitter. The ratio of C atoms to N atoms is _____

5 to 1

In carbon monoxide, there is always 1.33 g of oxygen for every 1 g of carbon. How many grams of carbon are in a 16.03 g sample of carbon monoxide? ____ g carbon

6.88

The percent by mass of sodium in table salt (NaCl) is 39.34 %. What is the percent by mass of chlorine?

60.66

In carbon dioxide, how many grams of oxygen would there be if there are 24 grams of carbon?

64

There are _______ basic SI base system units

7

Magnesium (24.30 g) reacts with hydrogen chloride (X g) to produce hydrogen gas (2.04 g) and magnesium chloride (96.90 g). How much hydrogen chloride was used in the reaction? ______ g HCl

74.42

Atoms of carbon-14 have ____ neutrons.

8

A statement best describes how protons were discovered?

A cathode ray tube revealed a ray of positive particles traveling in the opposite direction of negative electrons.

physical change

A change in a substance that does not involve a change in the identity of the substance

chemical change

A change in matter that produces one or more new substances (different composition)

physical property

A characteristic of a pure substance that can be observed without changing it into another substance

mixture

A combination of two or more substances that are not chemically combined, in any proportion

theory

A hypothesis that has been tested with a significant amount of data (why)

What is the difference between a hypothesis and a theory?

A hypothesis that is repeated multiple times with the same ending is turned into a theory / Hypothesis is a proposed explanation intended to be further tested. A theory is what is developed after testing to explain the results.

mass

A measure of the amount of matter that an object contains, SI base kilograms (kg)

weight

A measure of the force of gravity on an object

chemical symbol

A one or two letter representation of an element

filtration

A process that separates materials based on the size of their particles.

distillation

A process that separates the substances in a solution based on their boiling points

What is the difference between a theory and a law?

A theory is a repeated and confirmed hypothesis (with a why) while a law is a statement that is always true (even though there is not always a why) / Theory is often times the why and a law is always true but does not explain why.

What is an example of a physical change but not a chemical chemical change?

A water pipe freezes and cracks on a cold night

Who invented the first battery?

Alessandro Volta

Who invented dynamite?

Alfred Nobel

example of deductive reasoning

All men are mortal. Socrates is a man. Therefore, Socrates is mortal.

What product is not a heterogeneous mixture?

Ammonia

volume

Amount of space occupied by a sample of matter, SI base is cubic meter (m^3)

Hypothesis

An educated guess

What contribution to chemistry did Robert Boyle make?

Boyle's Gas Laws, created idea that small particles combine to form molecules

Who discovered the existence of the neutron?

Chadwick

Define "inductive reasoning" and give an example.

Collecting specific examples and drawing conclusions.

What would cause water to turn from a gas to a liquid?

Decreasing the water's temperature

A given chemical compound always contains the same elements in the exact same proportions by mass is the law of _____.

Definite proportions

Who was known as 'The Laughing Philosopher'?

Democritus

_____ introduced the idea of the atoms as basic building block of matter.

Democritus

What is pure research?

Done primarily to advance human understanding.

Explain how a hand-warmer works.

Exothermic Chemical reaction that releases thermal energy

A pure substance can be separated into components by physical methods. (T/F)

False

In mixtures, substances must combine in specific proportions (T/F)

False

Mixtures are all mixed uniformly and have an even composition throughout (T/F)

False

Titanium is softer than gold (T/F)

False

Who discovered the structure of insulin?

Fredrick Sanger

Sonia wanted to make ice pops. She filled cups with 150 mL of juice and put them in the freezer. How will freezing the juice affect its mass?

Freezing the juice will not change it's mass

______ can be highly compressed

Gas

Suppose you have three identical test tubes that contain equal masses of a solid, liquid, and gas form of the same substance. Which form of the substance has the largest volume and why?

Gas: It expands to fill the container

The mass ratio of hydrogen to oxygen in water (formula H2O) is 0.126 g hydrogen for every 1 g of oxygen. In another compound of hydrogen and oxygen called hydrogen peroxide, the mass ratio of hydrogen to oxygen is 0.063 g hydrogen for every 1 g of oxygen. What is a possible formula of hydrogen peroxide?

H2O2

example of inductive reasoning

Harold is a grandfather. Harold is bald. Therefore, all grandfathers are bald.

How did Aristotle improve the approach?

He was the first to make observations and he tried to understand what was happening / Carried out research and recorded data.

A _____ mixture consists of two or more phases.

Heterogeneous

Give one example of pure research.

How the universe formed? / Is there life on Mars?

Which of the following contains a single phase? I. substance II. homogeneous mixture III. heterogeneous mixture

I and II

When one or more substances undergo a chemical reaction, the:

Mass of the reactant decreases and the mass of the product increases but the total mass remains the same.

What chemical is missing in the diabetic patient?

Insulin

What is applied research?

Intended for a practical goal and application.

What is the health danger of breathing carbon monoxide?

It blocks oxygen from binding to hemoglobin.

Milk is uniformly mixed it contains several compounds--water, proteins, fats, and sugars. Is milk considered a substance or a mixture?

It is a mixture that can be separated by physical means

Why is gold considered valuable?

It is a very rare element, and is dangerous to mine

What happens to the lead in used car batteries?

It is recycled -it is put into a tank that separates it from the rest of the materials so it can be used again

Soil is a heterogeneous mixture. What best explains why?

It is unevenly mixed, so it does not have the exact same composition throughout the mixture.

Salt water is a homogeneous mixture. What best explains why?

It is uniformly mixed, so it has an even composition throughout.

which scientist discovered the electron?

JJ Thomson

metric prefixes come from _____ or _____ terms

Latin, Greek

A chemical compound is always found to be made up of the same elements combined together in the same fixed proportion by mass. This is known as the:

Law of definite proportions

area (A)

Length x Width (m^2)

The water cycle is a complex system. In it, water changes states. Sometimes it is a liquid. Sometimes it is a solid. Other times it can become a gas. What change occurs when water is boiled?

Liquid becomes a gas

What is the elixir of life?

Philosopher's stone (be able to turn metal into gold) thought to bring immortality

What is the relationship between the masses of protons and electrons?

Protons are much more massive than electrons.

Which of the following was/were used by the Greek philosophers in order to understand the world?

Reason

Before J.J. Thomson began gathering evidence about electrons in 1897, what did scientists know about atoms?

Scientists generally thought atoms were the smallest particles that could not be broken down any further.

Two examples of chemistry in daily life

Showering, cooking

When combined, iodine and tin were found to produce two different molecules. Both contained the same mass of tin, but one had twice as much iodine. The molecular formula for one of the molecules is SnI2 , what is the formula for the other molecule? (2 answers)

SnI or SnI4

Define "deductive reasoning" and give an example.

Specific prediction based on a general principle.

Who developed Kevlar?

Stephanie Kwolek

What was the first synthetic resin used for?

Sturdy and inexpensive dishware

Which statement(s) best describe why table sugar is considered a pure substance?

Sugar has the same chemical composition throughout, a bowl of sugar contains only one compound, and sugar cannot be separated further by physical means

What evidence from the cathode ray tube experiment support the claim that electrons have a negative charge?

The cathode ray bent away from a negatively charged plate. The cathode ray bent toward a positively charged plate.

Which of the following best describes how Thomson concluded that electrons are present in all atoms.

The charge-to-mass ratio of electrons is always the same constant, no matter which substances are used in the cathode ray tube.

Identify the law that explains the following observation: Nitrogen dioxide can be formed by reacting 14 grams of nitrogen with 32 grams of oxygen.

The law of definite proportions

Katie's teacher has asked her to identify an unknown substance. She thinks about the properties of matter that will help her identify the substance. She knows it is a colorless liquid. She thinks it may be water but knows there are many colorless liquids that are not water. What would inform Katie that the liquid is NOT water?

The liquid freezes at 32 degrees C

length

The measurement of the extent of something along its greatest dimension, SI base unit is meter (m)

Why do solids not change much when pressure is applied to them?

The particles in a solid are very closely packed

_______ energy is released when we burn natural gas.

Thermal

What kind of energy is released when we burn natural gas?

Thermal energy

What contributions were made by alchemists to chemistry today?

They laid the groundwork (production of gunpowder, ceramics, glass)

A mixture is not considered to be a pure substance. (T/F)

True

Dela is helping his Aunt Starr on an archeological dig. His aunt gives him a bucket containing sand, rocks, and artifacts. What is the best way for Dela to separate the sand from the other materials?

Use a screen to filter out the sand.

Are all solutions homogeneous mixtures?

Yes

Can homogeneous mixtures be separated into their components?

Yes

What happens when an electron is removed from an atom?

a positive charge remains

extensive property

a property that depends on the amount of matter in a sample

intensive property

a property that depends on the type of matter in a sample, not the amount of matter

The mass of a neutron is close to the mass of

a proton

scientific notation

a way to express numbers as the product of 2 numbers, coefficient multiplied by 10 to a power

Which property is NOT used to separate a mixture?

ability to undergo a chemical reaction

concentration (c)

amount/volume (mol/L)

What is electric current's SI base unit?

ampere (A)

(identify type of chemistry) measuring mercury in seawater

analytical chemistry

Zoe is using a spectrophotometer to precisely determine the levels of various chemicals in a sample of drinking water. Identify the type of chemistry.

analytical chemistry

What happens to the lead in car batteries?

batteries are taken to a plant where they are crushed, lead sinks to the bottom, is melted and used again

What did John Dalton contribute to the atomic theory?

believed all matter is made of atoms, all atoms of an element are alike, compounds form when atoms of different elements combine and chemical reactions involve rearranging atoms not a change in atoms

(identify type of chemistry) studying enzymes in cells

biochemistry

What blood test can be performed using material purchased from your local drugstore?

blood glucose test

Eliot is given a sample of unknown liquid to test in the laboratory. Eliot thinks that the liquid is water, but he isn't sure. What would be most helpful for Eliot to test in order to determine whether or not the liquid is water?

boiling point of the liquid

What is a hazard of lead?

brain damage, especially in children

What is the macroscopic world?

can be seen without a microscope (measured directly)

suspensions

can filter out, can see, heterogeneous, large particles

colloids

can't be filtered out, can see, homogeneous, medium particles

solutions

can't be filtered out, can't see, homogeneous, tiny particles

What is luminous intensity's SI base unit?

candela (cd)

What is the microscopic world?

cannot be seen without a microscope

What method would likely be used to separate a mixture of colored inks?

chromatography

What separation technique involves passing the mixture through a medium in which the components move at different rates?

chromatography

______ separates components in a mixture at different rates as they pass through a medium.

chromatography

How did Aristotle improve the approach of old philosophers when studying the material world?

collected his data and made systematic observations to understand what he was seeing

Butter is a mixture of proteins and fats that does not separate out when left alone. What type of mixture is butter?

colloid

Examples of intensive properties are ____ and _____

color, temperature

The "clusters" of Democritus are like what kind of material that we know of today?

compounds

During a chemical reaction, the law of _______ _______ states that the total mass of the products must be equal to the total mass of the reactant.

conservation of mass

solid

definite shape, definite volume, particles vibrate on fixed axes