U2 Important Vocab

Question 1

gas

Answer 1

no fixed volume or shape, lowest density, very compressible

Question 2

liquid

Answer 2

takes the shape of its container, sometimes compressible, higher density than gas

Question 3

solid

Answer 3

definite volume, not compressible, highest density

Question 4

evaporation - phase change

Answer 4

liquid to gas, based on BP, liquid can’t be recovered ex. separating salt from salt water

Question 5

condensation - phase change

Answer 5

gas (water vapor) to liquid

Question 6

melting - phase change

Answer 6

solid to liquid

Question 7

freezing - phase change

Answer 7

liquid to solid

Question 8

sublimation - phase change

Answer 8

solid to gas without being a liquid in between

Question 9

deposition - phase change

Answer 9

gas to solid without being a liquid in between

Question 10

elements

Answer 10

can’t be broken into simpler substances, composed of only 1 type of atom

Question 11

monatomic elements

Answer 11

elements made up of atoms ex. Au (gold)

Question 12

diatomic elements

Answer 12

elements made up of molecules ex. O2

Question 13

Allotropes

Answer 13

different forms of same element ex. Oxygen (O2) and Ozone (O3)

Question 14

compounds

Answer 14

two or more different elements chemically combined, can be broken down into simpler substances through chemical reactions
(2 or more different atoms)

Question 15

isomers

Answer 15

same formula but different structure ex. glucose and fructose ex. C6 H12 O6

Question 16

molecule

Answer 16

non-metals covalently bonded

Question 17

mixtures

Answer 17

physical combination of 2 or more different pure substances
substances retain their chemical properties, no chemical reactions between the substances and can be separated physically

Question 18

heterogeneous mixtures

Answer 18

visibly distinguishable parts, can be separated into homogeneous mixture or PS

Question 19

homogeneous mixtures

Answer 19

Have no visibly distinguishable parts, can be all 3 states of matter

Question 20

alloy

Answer 20

mixed metals ex. brass (made of copper and zinc)

Question 21

physical properties

Answer 21

can be observed or measured without changing the substance’s composition
ex. color, odor, density, melting, BP

Question 22

chemical properties

Answer 22

describes the way a substance may change or react to form new substances ex. flammability, fermentation, corrosion

Question 23

extensive properties

Answer 23

changing
depend on the amount of the sample ex. mass, volume, length, energy

Question 24

intensive properties

Answer 24

not changing
do not depend on the amount of sample ex. all chemical properties, density, BP, luster

Question 25

physical changes

Answer 25

physical appearence changes, but no composition ex. all phase changes, dissolution

Question 26

chemical changes (reactions)

Answer 26

transformed into a chemically different substance ex. combustion of gasoline, iron rusts, dissolving ionic compounds

Question 27

magnet

Answer 27

based on the magnetism of certain metals

Question 28

forceps (tweezers) or sift

Answer 28

based on the size of different substances

Question 29

solubility

Answer 29

based on how well a substance dissolves in a solution

Question 30

distillation

Answer 30

process that depends on differences in boiling points of substances, changes gas back to liquid

Question 31

filtration

Answer 31

process that separates a solid from a liquid due to their differences in sizes

Question 32

chromatography

Answer 32

has two phases: mobile phase (moves with the sample) and stationary phase (doesn’t move with the sample)
the components have different affinities (how it dissolves)
They pass through the system at different rates
Higher affinity to the mobile phase will travel up
In an example with water, filter paper, and ink - the mobile phase is the water (moving) and the stationary phase is the filter paper (not moving)

Question 33

heat

Answer 33

the energy used to cause temp. of an object to increase

Question 34

kinetic energy

Answer 34

energy created in motion

Question 35

potential energy

Answer 35

energy stored in objects

Question 36

temperature

Answer 36

reflects the random motions of the particles in a substance
measures heat

Question 37

heat and temperature are related because…

Answer 37

heat is transferred btw two objects due to a temp. difference, only stops transferring when the temp. becomes equal

they both measure each other

Question 38

exothermic process

Answer 38

heat is transferred out of system to surroundings (heat is lost)

Question 39

endothermic process

Answer 39

heat is transferred into the system from surroundings (heat is gained)

Question 40

heat of fusion

Answer 40

the energy required to melt a solid to a liquid

Question 41

heat of evaporation

Answer 41

energy required to evaporate a liquid to a gas

Question 42

centrifugation

Answer 42

a machine (centrifuge) used to separate substances in a liquid
Mixture is placed in test tubes and put into the machine
Inside of machine rotates very quickly causing particles to travel to the bottom of the tubes
The result is to separate a mixture into a solid pellet and a liquid into a supernatant.
The supernatant can then be poured into another container
Either part of the mixture can be saved

Question 43

precipitate

Answer 43

a solid formed as a result of centrifugation