Chem Test 1

Front 1

Which of the following statements about hypothesis is false?

A. A hypothesis must be testable in a way that is replicable by others.

B. A hypothesis is an explanation for a natural phenomenon.

C. A hypothesis should be created when the outcome for its test is known.

D. A hypothesis is an educated guess about why something happens

Back 1

C.

Front 2

Choose the true statement

A. A hypothesis always leads to a scientific theory.

B. A scientific theory summarizes a hypothesis that has been supported with repeated testing.

C. To be called a hypothesis, an explanation must be tested by multiple independent researchers.

D. The theory is established first followed by the hypothesis.

Back 2

B

Front 3

Scientific method

Back 3

The process that lies at the center of scientific inquiry

Front 4

Theory

Back 4

Is a set of tested hypothesis that give an overall explanation of some part of nature.

Front 5

Chemistry

Back 5

The science that deals with the materials of the universe and the materials that these materials undergo.

Front 6

Matter

Back 6

The stuff of which the universe is composed, the two characteristics are it has mass and occupies space.

Front 7

Three stages of matter

Back 7

Solid, liquid, gas

Front 8

Solid

Back 8

Rigid, has a fixed shape and volume

Front 9

Liquid

Back 9

Has a definite volume but takes the shape of its container

Front 10

Gas

Back 10

Has no fixed volume or shape; takes the shape and volume of its container

Front 11

Physical properties

Back 11

Boiling point, melting point, diamond is hard, a metal wire conducts electric current,

Front 12

Chemical properties

Back 12

Ability to format new substances, wood burning, rusting of steel, digestion of food, growth of grass in our yard.

Front 13

What state of matter is this?

Back 13

Liquid

Front 14

What state of matter is this?

Back 14

Solid

Front 15

What state of matter is this?

Back 15

Gas

Front 16

Back 16

Front 17

Classify each as a chemical or physical change

A. Milk turns sour

B. Wax is melted over a flame and them catches fire and burns

Back 17

A. Chemical

B. Chemical

Front 18

Elements

Back 18

Cannot be broken down into other substances by chemical means.

Front 19

Compounds

Back 19

Substances that have the same composition no matter where we find them. They are made out of elements and therefore can be broken down into elements through chemical changes. Example, water.

Front 20

Mixture

Back 20

Can be defined as something that has variable composition. Ex, wood is a mixture, wine is a mixture, coffee, and groundwater.

Front 21

Pure substance

Back 21

Always has the same composition. Pure substances are either elements or compounds. Pure water is a compound. Groundwater is a mixture.

Front 22

Solution

Back 22

Another word for mixture

Front 23

Heterogeneous mixture

Back 23

Contains regions that have different properties from those of other regions. Ex, when we pour sand into water, there will be an area that's mostly water and one that's mostly sand.

Front 24

Homogenous mixture

Back 24

Is the same throughout. Ex, when we pour salt into water, all the regions of the mixture have the same properties.

Front 25

Identify each as pure substance, homogenous mixture, or heterogeneous mixture.

A. Gasoline

B. Stream with gravel at the bottom

C. Air

D. Brass

E. Copper metal

Back 25

A. Homo

B. Hetero

C. Homo

D. Homo

E. Pure

Front 26

Distillation

Back 26

The process of boiling water to turn it to steam, and it condenses to pure water

Front 27

Is there a difference between a homogenous mixture of hydrogen and oxygen In a 2:1 ratio and a sample of water vapor?

Back 27

Yes, a mixture of hydrogen gas and oxygen is composed of 2 types of molecules. A sample of water vapor contains only 1 type of molecule, h2o. Even if there is 2 times as much hydrogen gas as oxygen gas in the sample, the molecules of h and o2 are distinct, whereas the 2h and o atoms in water are connected(bonded).

Front 28

Are all physical changes accompanied by chemical changes? Are all chemical changes accompanied by physical changes? Explain.

Back 28

No. Physical changes are not necessarily accompanied by chemical changes. However chemical changes are always accompanied by physical changes.

Front 29

_______ has a fixed shape and volume.

Back 29

Solid

Front 30

Matter in the ______ state has no shape and fills completely whatever container holds it.

Back 30

Gas

Front 31

Which of the following represents a chemical change?

A. Frying an egg

B. Diluting orange juice

C. Sublimation of dry ice

D. Molding melted silver

Back 31

A. Frying an egg

Front 32

How can you tell that a physical change has taken place?

Back 32

The properties of the starting and ending materials are the same.

Front 33

What is the difference between a hypothesis and a scientific theory?

Back 33

A hypothesis is a tentative proposal and a theory is a tested proposal.

Front 34

What is the difference between a scientific theory and a natural law?

Back 34

A theory explain s behavior and a law states a measure able relationship.

Front 35

Proton (p+)

Back 35

Positively charged subatomic particle found In the nucleus of the atom.

Front 36

Neutron (n)

Back 36

Neutral subatomic particle found in the nucleus.

Front 37

Electron(e-)

Back 37

Negatively charged subatomic particle found outside the nucleus.

Front 38

Back 38

Memorize the blue part

Front 39

If the number is a whole number move the decimal to the____

Back 39

Left

Front 40

If the number is a decimal move the decimal point to the _____

Back 40

Right

Front 41

If the decimal is moved to the right the exponent is_____

Back 41

Negative

Front 42

If the decimal is moved to the left the exponent is _____

Back 42

Positive