matter and energy

Question 1

matter

Answer 1

anything that takes up space and has mass
- exists in three phases: solid, liquid, and gas

Question 2

solid phase

Answer 2

• definite volume and definite shape
  
  • crystalline
  • packed tightly

Question 3

liquid phase

Answer 3

• definite volume and no definite shape
  
  • some disorder

Question 4

gas phase

Answer 4

• no definite volume and no definite shape
  
  • total disorder = entropy

Question 5

changes that can affect phases (these changes are physical changes)

Answer 5

1. temperature - affects how fast particles move
2. affects how packed the particles are

Question 6

endothermic

Answer 6

process that requires absorption of heat (heating process)

Question 7

exothermic

Answer 7

process that involves the release of heat (cooling process)

Question 8

endothermic changes (heat is absorbed)

Answer 8

1. melting (solid to liquid)
2. vaporization / evaporation (liquid to gas)
3. sublimation (solid to gas) – skips the liquid phase
   
   • ex: dry ice and iodine
     1) CO2 (s) => CO2 (g)
     2) I2 (s) => I2 (g)

Question 9

exothermic changes (heat is released)

Answer 9

1. freezing (liquid to solid)
2. condensation (gas to liquid)
3. deposition (gas to solid)

Question 10

matter (categorizing matter)

Answer 10

1. cannot be created nor destroyed, only change form
2. anything which occupies space and has mass
   - in chemical reactions the mass, charge, and energy of all matter are ALL conserved

Question 11

pure substance

Answer 11

a type of matter that has definite composition and the properties are the same throughout

Question 12

elements

Answer 12

made of one kind of atom
- CANNOT be broken down by ordinary means
ex: Au, Mg, Na or Diatomic Elements

Question 13

compound

Answer 13

a substances made of two or more elements that are chemically combined
ex: 2H2 + O2 => 2H2O

Question 14

mixture

Answer 14

physical combination of two or more distinct substances; compostion ALWAYS VARIES
ex: air, milk, sand, and glass
ex: NaCl (aq)

properties of a mixture:
1. formed by a physical combination
2. parts of a mixture retain their og properties
3. parts are separated by physical properties (ex: magnetism, density, size, boiling point)
4. NO definite formula; composition varies

Question 15

homogenous

Answer 15

mixtures were all parts look the same and particles are evenly distributed
- ex: air, milk, NaCl (aq)

Question 16

heterogeneous

Answer 16

a mixture where you can see the parts and the particles are unevenly distributed
- ex: rocks, soil, and sand

Question 17

physical properties

Answer 17

characteristics which can be observed without producing a new substance
- ex: color, odor, taste, density (d=m/v)

Question 18

solubility

Answer 18

ability to dissolve (forms a mixture)

Question 19

brittleness

Answer 19

ability to shatter when struck

Question 20

luster

Answer 20

shine

Question 21

magnetism

Answer 21

ability to be attracted to a magnet

Question 22

malleability

Answer 22

ability to be hammered into a sheet and not fall apart
- ex: aluminum foil

Question 23

ductility

Answer 23

ability to be drawn into a wire

Question 24

conductivity

Answer 24

ability to carry a current or heat

Question 25

tenacity

Answer 25

ability to resist being pulled apart

Question 26

sublimation

Answer 26

can change from a solid to a gas without melting at a certain temperature

Question 27

boiling point

Answer 27

temp at which liquid turns to a gas

Question 28

melting point

Answer 28

temp at which solid turns to a liquid

Question 29

chemical properties

Answer 29

characteristics which describe how a substances **reacts** and **fails to react** with other substances

Question 30

physical change

Answer 30

a change in the appearance but **NOT** in major properties or composition - ex: H2O (s) + heat => H2O (l) - boiling evaporation - phase changes - grinding / chopping - dissolving

Question 31

chemical change

Answer 31

a change in which one or more substances **form** with totally **new** properties and compounds - burning - digestion - rusting / corrosion (oxidized) - souring of milk - decaying

Question 32

filtration (size)

Answer 32

used to separate misture components based on **SIZE** (heterogenous mixture) - small particles (filtrate) pass through the filter paper - large particles (residue) remains on the filter paper

Question 33

density

Answer 33

a separatory funnel is used to separate parts of a mixture based on differences in **DENSITY**

Question 34

paper chromatography

Answer 34

separates a mixture basted on different attractions to the paper - molecules has a difference in charge/polarity

Question 35

distillation (boiling point)

Answer 35

used to separate **homogenous** mixtures based on **boiling points** - solid dissolved in liquid - two or more liquids combined

Question 36

temperature

Answer 36

the measure of the **average kinetic energy** (energy of motion) of a substance's particles - measured in fahrenheit, celsius, and/or kelvin

Question 37

heat

Answer 37

the amount of energy **transferred** from on substances to another - measured in joules or calories - **moves from a higher temp to lower temp**

Question 38

absolute zero

Answer 38

temp at which all molecular motion stops

Question 39

kinetic energy

Answer 39

energy of motion; increases as temp increases

Question 40

potential energy

Answer 40

stored energy in bonds; increases as the distance between the molecules increases

Question 41

specific heat

Answer 41

amt of hear energy in joules required to change the temp of 1 gram of a particular substance by 1 degree **(J/g ⋅ °C )** - specific hear of water = 4.18 J/g ⋅ °C

Question 42

measurement of heat energy

Answer 42

**Q = mCΔT** 1. Q = amt of heat gained or lost (joules / J) 2. m = mass (grams) 3. C = specific heat of a substances (J/g ⋅ °C ) 4. Delta T = change in temp (final - intial)

Question 43

heat of fusion

Answer 43

amt of heat (J/g) required to melt 1 gram of a substance - equal to freezing **Q = m x Hf**

Question 44

heat of vaporization

Answer 44

amt of heat (J/g) required to vaporize 1 gram of a substance - equal to condensation **Q = m x Hv