Unit Zero: Intro to Chem

Question 1

Quantitative

Answer 1

Involves a measurement (number)

Observations are made with intruments such as scales, rulers, thermometers etc.

Question 2

Qualitative

Answer 2

Describes phyical descriptions, descriptions about shape, color, size, etc.

Question 3

Matter

Answer 3

Anything that takes up space and has mass

• particles of matter are always in motion
• kinetic energy (speed) of particles increases as temperature increases

Question 4

Solid

Answer 4

MOTION OF PARTICLES:
Particles vibrate but don't move past each other
SHAPE: 
definite shape
VOLUME:
definite volume
particles are tightly packed

Question 5

Liquid

Answer 5

MOTION OF PARTICLES:
Particles move by sliding past each other
SHAPE:
indefinite shape
VOLUME:
definite volume
particles are more loosely packed than solid but not as loose as gases

Question 6

Gas

Answer 6

MOTION OF PARTICLES:
Particles are separate from each other and move throughout the container
SHAPE: 
indefinite shape
VOLUME:
indefinite volume
Most loosely packed particles

Question 7

Vapor

Answer 7

The gaseous phase of a substance that exists as a solid or liquid at room temperature

Question 8

Physical property

Answer 8

a quality or condition of a substance that can be observed or mesured without changing the subtance’s composition
Ex. color, solubility, odor, hardness, density, melting/boiling point

Question 9

Chemical property

Answer 9

can only be observed when a substance undergoes a chemical change
Ex. flammability, decomposition, oxidation, explosiveness, corrosion

Question 10

Extensive property

Answer 10

depends on the amount of matter present

Ex. volume, mass

Question 11

Intensive property

Answer 11

Depends on the identity of the sunstance, not the amount

Question 12

Physical change

Answer 12

Change which allows given material without changing its composition
Ex. cutting/tearing, grinding, changes of state

Question 13

Chemical change

Answer 13

Chemical composition of a substance changes (you end with a different subtance than you started with)

Question 14

Signs of a chemical change

Answer 14

• Emergy change: energy is often given off or absorbed as heat
• Color change
• Odor production
• Production of gas (often as fizz or bubbles)
• Irreversibility: cannot proceed back to the original form

Question 15

Phase change: solid to liquid

Answer 15

melting

Question 16

Phase change: liquid to solid

Answer 16

freezing

Question 17

Phase change: liquid to gas

Answer 17

vaporizing

Question 18

Phase change: gas to liquid

Answer 18

condensing

Question 19

Phase change: solid to gas

Answer 19

sublimation

Question 20

Phase change: gas to solid

Answer 20

deposit

Question 21

Law of conservation of matter

Answer 21

In all chemical and physical changes, matter cannot be created or destroyed

Question 22

Pure substance

Answer 22

Matter with uniform and constant composition

Each subtance has a unique set of chemical and physical properties

Question 23

Element

Answer 23

• Simplest form of matter that can exist under natural conditions
• Can’t be broken down into simpler substance
• Building blocks for all other subtances

Question 24

Compound

Answer 24

• 2 or more different elements chemically combined to form a new substance
• Can be separated into a simpler subtanvr only by chemical means
• Has properties that are different from the elements they are made from

Question 25

Mixture

Answer 25

Combination of 2 or more pure substances - Each substance retains its individual chemical properties - Variable composition - Can be separted by physical means

Question 26

Heterogeneous mixture

Answer 26

Uneven blend of 2 or more subtances Individual substances remain distinct Ex. sand, chocolate chip cookies, water

Question 27

Homogenoeous mixture

Answer 27

Even blend of 2 or more pure substances Uniform composition Very small particles that don't separate

Question 28

What are 5 signs that a chemical reaction has occurred?

Answer 28

- Energy change - Color change - Odor production - Production of gas - Irreversibility

Question 29

Filtration

Answer 29

USes a porous barrier to separate a solid from a liquid

Question 30

Distilation

Answer 30

Based on differences in the boiling points of the substances

Question 31

Centrifuge

Answer 31

Spinning that separates the composition of a mixture based on their density

Question 32

Decanting

Answer 32

Pouring a liquid off of a solid

Question 33

Chromatography

Answer 33

Based on the ability of each substance to travel or be drawn across a surface