Chemistry Unit 2

Ni

Nickel

N

Nitrogen

NaCl: phenol (C6H6O): C2H6: . Ca3(PO4)2: formaldehyde (CH20): MgCO3: vitamin D2 (C27H40O): mercury sulfate (HgS): butane (C4H10): sand (SiO2): water (H2O):

inorganic organic organic inorganic organic inorganic organic inorganic organic inorganic inorganic

Elements listed in vertical columns of the periodic table: have similar chemical properties have similar physical properties are metals can combine with each other chemically

have similar chemical properties

metal

the group of elements that are good conductors of electricity and heat

nonmetal

the group of elements that are poor conductors of electricity and heat

C

Carbon

Au

Gold

physical change

a change in shape, size, or physical characteristics but remaining same substance

element

a primary substance that cannot be divided into separate substances

Fe

Iron

The usual units of density are:

g/cm3

Which of the following is not a phase change? melting of snow evaporation of water from the ocean condensation of water vapor to form clouds hydrogen and oxygen gas combining to form water vapor

hydrogen and oxygen gas combining to form water vapor

The rocks and minerals of the Earth consist of _________ compounds.

inorganic

NaCl: phenol (C6H6O): C2H6: Ca3(PO4)2: formaldehyde (CH20): MgCO3:

inorganic organic organic inorganic organic inorganic

A 56 g sample of peanut oil has a volume of 60.9 cm³. Calculate the density of the peanut oil. Remember to use the correct number of significant digits in your answer.

0.92 g/cm3

A sample has a mass of 35.4 g and a volume of 36.82 mL. What is the density of the sample?

0.961 g/mL

Helium has a density of 1.79 x 10-4 g/mL at standard temperature and pressure. A balloon has a volume of 6.3 liters. Calculate the mass of helium that it would take to fill the balloon.

1.1 g

Chlorophyll a is one of the green pigments found in plants. Chlorophyll a has the molecular formula /C55/H72/Mg/N4/O5/. How many atoms are in this molecule?

137

How many naturally occurring elements are there?

92

Al

Aluminum

U

Uranium

atom

smallest unit of an element

Which of the following was not a goal of the alchemists? to change lead into gold to discover a means to prolong life to discover new ways to use electricity to discover a universal cure for disease

to discover new ways to use electricity

compound

two or more elements joined together such that the elements have lost their individual identity

What does the term "compound" mean?

two or more elements joined together such that the elements have lost their individual identity in favor of a new set of properties

mixture

two or more substances dispersed in one another but each retaining their own identity

There are _____ naturally occurring elements.

92

He

Helium

O

Oxygen

Sn

Tin

Ba

Barium

Gelatin has a density of 1.27 g/cm3. If you have a blob of gelatin dessert that fills a 2.0-liter bottle, what is its mass?

2,500 g

Researchers have discovered that a moon rock brought back by the Apollo astronauts has a mass of 5.671 kg and a volume of 1,698 cm3. What is the density of the rock? Remember to use the correct number of significant digits in your answer.

3.340 g/cm3

A gold nugget has a volume of 20.0 cm3 and its density is 19.3 g/cm3. What is the mass of the gold nugget?

386 g

Ca

Calcium

Cl

Chlorine

Cu

Copper

All organic compounds are found in living organisms.

False

Density is inversely proportional to pressure.

False

Plastic products are made from inorganic compounds.

False

The Mohs hardness scale increases linearly from 1 to 10.

False

The density of a gas cannot be measured.

False

The physical properties of a compound are similar to those of its elements.

False

H

Hydrogen

Why does a weather balloon filled with Helium rise?

Its density is less than air.

Why does ice float after it crystallizes?

Its density is less than water.

Mg

Magnesium

Mn

Manganese

The name of the commonly used hardness scale is:

Mohs

Plants make glucose by a chemical process called:

Photosynthesis

grinding glass: rusting of iron: burning a candle: sanding wood:

Physical Chemical Chemical Physical

melting ice: souring of milk: digesting food: evaporating water:

Physical Chemical Chemical Physical

K

Potassium

All atoms of the same element have the same number of:

Protons

Ag

Silver

The softest and hardest minerals are:

Talc, diamond

metals

good conductors of electricity

Diamond will scratch quartz.

True

Hardness and density are physical properties.

True

Hardness is a physical property.

True

Hardness may be defined as the resistance of a material to scratching.

True

Iron filings can be separated from a mixture with sulfur by using a magnet.

True

Platinum will scratch gold.

True

The various components of a mixture do not combine chemically.

True

Unknown compounds can usually be identified based solely on their physical properties.

True

The smallest unit that can exist as an element and still have the properties of that element is a(n):

atom

Zn

Zinc

phase change

a change from one state of matter to another

alloy

a homogeneous mixture of elements with metals to form metallic solids

solution

a homogeneous mixture, usually a liquid with some substance dissolved in it

Law of Constant Composition

a pure compound consists of exactly the same elements in the exact same ratios by mass

Which has the greater density? air at sea level air at 20km altitude

air at sea level

alchemy

an ancient study or art which attempted to combine science and philosophy to solve worldly problems

Ar

argon

For each item, choose whether the change is a physical change or a chemical change. exploding firecracker: mowing grass: breaking a window: spreading butter on toast: burning wood in a fireplace: acid rain corroding gravestones:

chemical physical physical physical chemical chemical

compound

chemical combination of elements

heterogeneous

composed of dissimilar parts which can be separated easily

element

consists of only one substance

Which of the following physical properties would tell you about an element's mass per unit volume ratio? hardness boiling point crystalline shape density all of the above

density

The process of passing electricity through water to chemically separate it into hydrogen and oxygen is called what?

electrolysis

A substance which is made up of identical atoms is a(n):

element

An atom: is the smallest whole unit of matter can form one or more elements is the smallest whole unit of matter with the properties of a specific element all of the above

is the smallest whole unit of matter with the properties of a specific element

As a substance changes phase from gas to liquid to solid:

its density generally increases

Pb

lead

Using your knowledge of symbols, determine which compound listed must contain both copper and oxygen. glucose, C6H12O6 chalcopyrite, CuFeS2 malachite, Cu2CO3(OH)2 calcite, CaCO3

malachite, Cu2CO3(OH)2

Which is the correct definition of density?

mass/density

Hg

mercury

Inorganic compounds which are found in the earth are called:

minerals

colloid

mixture in which the suspended particles are too small to be seen with the naked eye

suspension

mixture that separates into individual components with time

A classification of matter which stipulates that the compound must contain carbon is called

organic

All man-made and most carbon-based compounds are

organic

Alexandria

original site of alchemy

nonmetals

poor conductors of electricity

Hardness is indirectely related to: surface roughness strength of chemical bonds mass weight

strength of chemical bonds

Hardness is related to:

strength of chemical bonds

atom

the simplest unit of an element that still retains the properties of that element

chemical change

the starting materials completely lose their properties to form new substances