Chapter 1 Pt 1 Essential Concepts Assignment

When 5.0 grams of calcium are burned in oxygen, 7.0 grams of calcium oxide result. What mass of oxygen reacted? Select the correct answer below: 1.0 grams 2.0 grams 5.0 grams 7.0 grams

2.0 grams The material gained 2.0 grams of mass which must have come from the oxygen.

Which of the following measurements would be a reasonable guess for the diameter of a gold atom? Select the correct answer below: 3×108 m 3×10−10 m 3×105 m 3×10−3 m

3×10−10 m Atoms are microscopic particles that require specialized microscopes to visualize. Of the four lengths presented, only 3×10−10 m fits this description. The next shortest length, 3×10−3 m, is equal to 3 millimeters and can be seen by the naked eye.

Which of the following is true? Select the correct answer below: A law is formed when testing yields consistent observations. A law is formed when additional testing supports the hypothesis. A theory is formed when testing yields one observation. None of the above

A law is formed when testing yields consistent observations.

Which of the following statements about atoms and molecules are true? Select all that apply. Select all that apply: All substances are composed of molecules. Atoms in a molecule are held together by chemical bonds. All molecules are composed of atoms. All substances are held together by chemical bonds.

Atoms in a molecule are held together by chemical bonds. All molecules are composed of atoms. A molecule is defined as two or more atoms joined by strong forces called chemical bonds.

How could Antoine Lavoisier, the French scientist credited with proposing the law of conservation of matter, have demonstrated this law? Select the correct answer below: Carefully measuring the mass of reactants before a reaction and the mass of the products after a reaction in a sealed system Burning wood to show that both ash and smoke are produced Proving E=mc2 to demonstrate that mass can be converted into energy Discovering the existence of anti-matter

Carefully measuring the mass of reactants before a reaction and the mass of the products after a reaction in a sealed system Antoine Lavoisier is credited with proposing the law of conservation of matter. He performed experiments where he meticulously measured the masses of reaction reactants and products in a sealed system, so that no gas could escape. His demonstration that the mass of the reactants was equal to the mass of products supported the law of conservation of matter.

Which of the following is a phase of matter? Select all that apply. Select all that apply: plasma solid liquid gas

Correct answer: plasma solid liquid gas

Who was the first to propose the idea of atoms? Select the correct answer below: Aristotle Democritus Plato Socrates

Democritus The idea of Democritus was actually criticized by others of his time.

A pattern that has been established based on verified experimental data that describes an observation but does not provide an explanation as to the reason why said observation occurs is a _________. law theory hypothesis none of the above

Law

Which of the following events fail to follow the law of conservation of matter? Select the correct answer below: Burning wood for a fire Freezing water into ice cubes The decomposition of MgCl2 into Mg and Cl2 None of these

None of these All of these events follow the law of conservation of matter.

Through the complete electrolysis of a sample of pure water, a student collects 14.0 grams of hydrogen gas and 112.0 grams of oxygen gas. What mass of water (in grams), if it reacted completely, was initially present? (The electrolysis of water is the use of an electric current to decompose it into its component elements.) Report your answer to the nearest tenth.

Since both the hydrogen gas (H2) and oxygen gas (O2) came from water (H2O), the original mass of water must be equal to their sum. Since we are adding two numbers, we must follow the rule for significant figures for addition, which requires that we report the answer using the same number of decimal places as the value with the least number of decimal places, or to the nearest tenth. Therefore: mass of water=mass of hydrogen gas+mass of oxygen gas=14.0 g H2+112.0 g O2=126.0 g H2O

Which of the following statements is true? Select the correct answer below: Theories attempt to explain observations. Laws are briefer theories. Observations generally do not support theories Laws attempt to explain hypotheses.

Theories attempt to explain observations.

One way to measure mass is to use: Select the correct answer below: a balance a graduated cylinder a stopwatch a thermometer

a balance With a balance, we can compare the mass of an object with a standard mass. A graduated cylinder measures volume, a stopwatch measures time, and a thermometer measures temperature.

Which of the following is NOT a substance made of one type of molecule. Select the correct answer below: carbon dioxide glucose water a cell within the human body

a cell within the human body A cell is a collection of many different types of molecules.

A large change in temperature (not resulting from external heating) with the appearance of gas bubbles is most likely an indication of: Select the correct answer below: a chemical change only physical changes occurring molecules are undergoing physical changes none of the above

a chemical change A large change in temperature with the appearance of gas bubbles indicates that a chemical change has most likely occurred.

Which of the following terms describes the smallest particle of a substance that still retains the chemical properties of that substance? (Select all that apply.) Select all that apply: a mixture a molecule an atom a neutron

a molecule an atom Depending on whether the substance in question is an element or a compound, either an atom or a molecule is the smallest particle of that substance that retains its chemical properties. A substance cannot decompose into protons, neutrons and electrons without changing its very nature.

A strong magnet placed under a piece of paper makes a three-dimensional pattern in iron filings that are placed on top of the paper. This is an example of which of the following? Select the correct answer below: a change in an extensive property a change in an intensive property a chemical change a physical change

a physical change A physical change is a change in the state or properties of matter without any accompanying change in chemical composition. In the organization of the filings into a three-dimensional form by the magnet, there is no chemical change. Also, none of the extensive or intensive properties of the magnet or filings change.

Which of the following is a molecule? Select the correct answer below: water ozone glucose all of the above

all of the above Water, ozone, and glucose are all molecules, as they are all comprised of more than one atom.

The smallest unit of matter that is indivisible without utilizing a nuclear reaction is known as: Select the correct answer below: an atom a molecule a mixture a compound

an atom The atom is the smallest unit of an element. Molecules, mixtures, and compounds can be broken down into smaller constituents with relative ease.

What is the smallest particle that an element can be divided into? Select the correct answer below: compound electron atom neutron

atom An atom is the smallest particle that an element can be divided into.

he smallest particle of an element that has the properties of that element is called a(n): Select the correct answer below: proton electron atom molecule

atom The atom is the smallest unit of an element. A proton and electron are subatomic, and a molecule is a combination of atoms.

Sugar and water, with appropriate heat, can create caramel. In this example, sugar is undergoing a ___________. Select the correct answer below: electrical change kinetic change chemical change physical change

chemical change Sugar and water, when forming caramel, are undergoing a chemical change as the product is different than the reactants.

Which of the following is a physical change? Select all that apply. Select all that apply: chopping wood bending metal cutting a cake frying an egg

chopping wood bending metal cutting a cake Chopping wood, bending metal, and cutting a cake are all physical changes because the composition of the material isn't chemically changing. The changes that occur when frying an egg cannot be reversed and are therefore a chemical change.

Which of the following could be considered a chemical change? Select the correct answer below: dew condensing on a leaf mixing sugar in with your tea coal burning water evaporating from a pond on a hot day

coal burning Phase changes and mixing of substances are physical processes. When coal burns, carbon atoms form new chemical bonds to oxygen atoms, which is a chemical process.

ll of the following are extensive properties EXCEPT: Select the correct answer below: size color weight length

color Color is an intensive property that does not depend on the amount of matter present.

Which of the following is NOT a physical property? Select the correct answer below: combustibility conductivity malleability elasticity

combustibility Combustibility is the measure of how readily something will burn in the presence of oxygen, which is a chemical reaction. Therefore combustibility is a chemical property.

Where would you be "weightless"? Select the correct answer below: the Moon the Sun the bottom of the ocean deep space

deep space Only in deep space, far away from any source of gravity, would there be no gravitational force to give your body any weight. You would still have mass, but you would be effectively weightless.

Which of the following is measured using Newtons (a unit of force)? Select the correct answer below: mass weight density volume

weight

Which is an intensive property? Select the correct answer below: mass shape length density

density No matter how much of a substance is present, it will have the same density. The other characteristics will change according to the quantity.

Intensive properties can be: Select the correct answer below: physical properties chemical properties either physical or chemical properties none of the above

either physical or chemical properties Intensive properties can be either physical, like color, or chemical, like combustibility.

Which of the following is NOT a likely indicator of a chemical change? Select the correct answer below: the formation of a precipitate a color change the change in shape of a malleable metal the release of gas without adding heat or lowering the pressure

he change in shape of a malleable metal The bending of a piece of metal, like a paper clip, is not a chemical change. Only when a new substance is formed, evidenced by a new material present or a change in color, can a chemical change be guaranteed.

Characterize the following statement: If you drink coffee before going to bed, it will take longer to fall asleep. Select the correct answer below: observation hypothesis theory law

hypothesis

When a change in a physical property is observed, Select the correct answer below: it could be because of a physical change. it must be because of a chemical change. it must be because of a chemical change and a physical change. it could be caused by a change that is considered both physical and chemical.

it could be because of a physical change. An observed change to a physical property like phase, hardness, or density could be caused by a physical change like a phase transition or a heating. It cannot be both because a physical change is one that does not include any accompanying change in its chemical composition.

Which of the following observations about a basketball is NOT an example of an intensive property? Select the correct answer below: it is orange it is difficult to compress it is at room temperature it has a mass of 600 grams

it has a mass of 600 grams The mass of the basketball would change if it were smaller, so it is an extensive property. The other examples would not change with changing size.

All of the following are intensive properties EXCEPT: Select the correct answer below: melting point density length color

length Melting point, density, and color are intensive properties that are not dependent on the amount of matter present.

Which phase of water has the highest density? Select the correct answer below: solid liquid gas no difference

liquid For water, the liquid phase is more dense than the solid, which is why ice floats. A gas is far less dense, as the particles are very far apart.

The image below was captured over a hot mug of coffee on a cold morning. Which state(s) of matter are present in the image? Select all that apply. An image of a curling stream of greyish blue steam, like the steam from a cup of coffee, is shown. Select all that apply: plasma solid liquid gas

liquid gas The image shows steam condensing as it hits the cool air. Pure steam, which is in the gas phase, is invisible. The cloudy appearance comes from droplets of liquid water that form when the steam cools upon mixing with cold air.

Which of the following is measured in grams or kilograms? Select the correct answer below: mass weight density volume

mass Mass is measured using grams or kilograms.

Which of the following is an example of an extensive property of a substance? Select all that apply: mass temperature length volume

mass length volume Mass, volume, and length are extensive properties because they depend on the amount of a substance present in a sample. Temperature is an intensive property because it does not depend on the amount of substance. For example, imagine you have 1g of boiling water and 1kg of boiling water in identical containers. 1g of boiling water has the same temperature as 1kg of boiling water, but 1g of boiling water has less mass, less volume, and less depth (if we consider depth to be a length).

Which is an intensive property? Select the correct answer below: volume melting point weight heat

melting point Recall that an intensive property is a property of matter that is independent of the amount of substance in a sample. The melting point of a substance is an intensive property because it does not depend on the amount of substance present. Heat, volume, and weight are extensive properties because they depend on the amount of substance in a sample.

The characteristics of atoms are responsible for the following aspects of a type of matter, EXCEPT: Select the correct answer below: color density monetary value luster

monetary value Monetary value is a man-made concept.

The volume of water in a graduated cylinder is an example of what type of property? (Select all that apply.) Select all that apply: extensive chemical physical intensive

physical Volume is an example of both a physical property and an extensive property because it is dependent on the amount of water in the cylinder (extensive) and it is not associated with a change in chemical composition (physical).

Which physical form(s) of matter have neither a definite volume nor definite shape? Select all that apply: plasma solid liquid gas

plasma gas A physical form of matter that does not have a definite volume or shape is gas. Like a gas, plasma also lacks a definitive volume or shape.

Which of the following can be characterized as a physical change? Select the correct answer below: a copper pipe rusts milk goes sour firewood burns sweat evaporates from your skin

sweat evaporates from your skin Sweating is an example of a phase transition (from liquid to gas) which is a physical change. The rest of the options are examples of chemical changes.

Which of the following is/are example(s) of an intensive property of a substance? Select all that apply: mass temperature color volume

temperature color If the property of a sample of matter does not depend on the amount of matter present, it is an intensive property.

In order to be valid, a hypothesis must be: Select the correct answer below: long testable manipulated all of the above

testable

Today, the meter is based on: Select the correct answer below: a meter stick the height of a king a fraction of the distance from the equator to the north pole the distance light travels in a particular fraction of a second

the distance light travels in a particular fraction of a second

If you boil an entire sample of water, the steam that results will have: Select the correct answer below: less mass than the water more mass than the water the same mass as the water impossible to predict

the same mass as the water The law of conservation of matter tells us that mass is conserved as matter changes forms. Therefore, all the water molecules in the steam will have the same mass as when they were in the liquid form.

You examine a substance and generate the following results. Which of the following results describes a chemical property of that substance? Select the correct answer below: the substance emits a gas when dropped in water the substance is dark green the substance is sour to the taste the substance has a pleasant odor

the substance emits a gas when dropped in water If a gas is emitted, this indicates a chemical reaction has occurred, so assessing this reactivity is an example of a chemical property.

Which of the following is dependent on the effect of gravity? Select the correct answer below: mass volume weight density

weight