Chapter 1 - Matter & Change

Question 1

Define chemistry:

Answer 1

the study of matter: its composition, structures, properties, changes it undergoes, and energy accompanying these changes.

Question 2

Define matter:

Answer 2

anything that has mass and volume.

Question 3

Define element:

Answer 3

pure substance that cannot be physically or chemically broken down.
- made up of atoms with the same atomic number and same number of protons

Question 4

What is an example of an element?

Answer 4

carbon

Question 5

What are the three main types of elements?

Answer 5

metals, nonmetals, and metalloids

Question 6

List some of the characteristics of metals:

Answer 6

• ductile (able to be drawn out into a thin wire)
• malleable (hammer into thin sheets)
• tensile strength (resist breaking under pressure)
• good conductors of heat & electricity
• luster (shiny)

Question 7

List some of the characteristics of nonmetals:

Answer 7

• poor conductors of heat & electricity
• brittle (shatter easily)
• Group 18 (Noble Gases; nonreactive)

Question 8

List some of the characteristics of metalloids:

Answer 8

• possess some characteristics of metals and nonmetals
• utilized as semiconductors to carry electric current

Question 9

Define molecule:

Answer 9

consists of two or more elements that are bonded together.

Question 10

Give an example of a molecule:

Answer 10

O2

Question 11

What are the seven diatomic molecules?

Answer 11

Br, I, N, Cl, H, O, F

Question 12

Define compound:

Answer 12

a pure substance that consists of two or more different atoms bonded together in fixed proportions.
- can be chemically separated/decomposed into a simpler substance; always homogeneous

Question 13

What is an example of a compound?

Answer 13

H2O

Question 14

Define homogeneous mixture:

Answer 14

even distribution of two or more different substances mixed together.

Question 15

List a few examples of a homogeneous mixture:

Answer 15

salt water, water, air, stainless steel, sugar in water, Kool-Aid, et cetera.

Question 16

Define heterogeneous mixture:

Answer 16

uneven distribution of two or more different substances mixed.

Question 17

List a few examples of a heterogeneous mixture:

Answer 17

oil and water, granite, wood, chicken noodle soup.

Question 18

What methods can be used to separate a homogeneous mixture?

Answer 18

distillation, evaporation, crystallization, chromatography.

Question 19

What methods can be used to separate a heterogeneous mixture?

Answer 19

filtration, decantation.

Question 20

Define physical property:

Answer 20

characteristics that can be observed or measured without changing the identity of the substance.

Question 21

What is an example of a physical property?

Answer 21

melting or boiling property

Question 22

Define physical change:

Answer 22

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

Question 23

What are some examples of physical changes?

Answer 23

grinding, cutting, melting and boiling a material.

Question 24

Define chemical property:

Answer 24

a substance’s ability to undergo changes that transform it into different substances.

Question 25

What is an example of a chemical property?

Answer 25

the ability of charcoal to burn in air.

Question 26

Define chemical change:

Answer 26

a substance is converted into different substances.

Question 27

What is an example of a chemical change?

Answer 27

carbon and oxygen react to produce carbon dioxide, water vapor, and ash that did not react remains.

Question 28

Define the Kinetic Molecular Theory:

Answer 28

particles of matter are always in motion.

Question 29

What crucial components make up the Kinetic Molecular Theory?

Answer 29

• the higher the temperature of the substance is, the faster the particles move
• at the same temperature, more massive particles move slower than less massive ones

Question 30

What does a solid have?

Answer 30

definite shape and volume

Question 31

What does a liquid have?

Answer 31

definite volume, but indefinite shape

Question 32

What does a gas have?

Answer 32

no definite shape or volume

Question 33

Define the heating curve:

Answer 33

shows a change of a substance starting with the substance as a solid. Changes represented on a heating curve are endothermic because heat is being absorbed by the substance.

Question 34

What does it mean if an endothermic reaction is happening?

Answer 34

heat is being absorbed

Question 35

Define the cooling curve:

Answer 35

shows a change of a substance starting with the substance as a gas. Changes represented on a cooling curve are exothermic because heat is being released by the substance.

Question 36

What does it mean if an exothermic reaction is happening?

Answer 36

heat is being released