Foundations of CHem

Question 1

Matter

Answer 1

anything that has mass and takes up volume

Question 2

Composition

Answer 2

the arrangement, type, and ratio of atoms in molecules of chemical substances
Ex: H2O

Question 3

Structure

Answer 3

the way atoms are arranged within molecules

Question 4

Atoms

Answer 4

fundamental units of matter

Question 5

compounds

Answer 5

substances made up of more than one element bound together by fixed ratios
Ex: CO2
-uniform properties/fixed ratios of elements and are pure substances

Question 6

Molecules

Answer 6

atoms bound tightly together behaving as a single unit

Question 7

Pure Substances

Answer 7

materials composed of one element or one compound

Question 8

Mixtures

Answer 8

contains one or more substances and the substances are not bound by a fixed ratio
-can be separated into their individual components without changing their identities

Question 9

fixed ratio

Answer 9

used to compare the amount of elements in a chemical formula
Mixtures are not bound by fixed rations while compounds are

Question 10

Homogeneous Mixtures

Answer 10

components that are easily blended out
-has uniform properties throughout (equal properties)

Question 11

Heterogeneous Mixtures

Answer 11

regions with significantly different compositions

Question 12

Filtration

Answer 12

separating substances through filters (seperating a homogeneous mixture)

Question 13

Solids

Answer 13

has a definite shape and volume

Question 14

liquids

Answer 14

has a definite volume but not a definite shape

Question 15

gases

Answer 15

does not have a definite shape and volume

Question 16

Vaporization

Answer 16

liquid -> gas

Question 17

Condensation

Answer 17

gas -> liquid

Question 18

Physical properties

Answer 18

properties of a substance that we can measure without altering the identity of the substance

Question 19

Chemical Properties

Answer 19

properties that we can’t measure without changing the identity of the substance. A substance with new properties must be the result of a reaction.

Question 20

potential energy

Answer 20

the energy that is stored
-substances with more potential energy are more likely to react

Question 21

kinetic energy

Answer 21

energy of motion
-the faster the object is moving, the more potential energy is created

Question 22

chemical changes

Answer 22

a change where a new substance is formed after the reaction

Question 23

physical changes

Answer 23

formation or separation of mixtures

Question 24

heat energy

Answer 24

involves kinetic energy of the particles in a substances
-PE is converted into KE

Question 25

hypothesis

Answer 25

a tentative explanation that has not been tested

Question 26

theory

Answer 26

an idea supported by experimental evidence (paradigm)

Question 27

scientific law

Answer 27

a statement that describes the observations that are true in widely varying circumstances