ch.2 sec 3

Question 1

when the appearance or form of a substance has changed but no new substance is produced

Answer 1

physical change

Question 2

what type of change are all changes of states of matter

Answer 2

physical change

Question 3

A change in matter that produces or more new substances

Answer 3

chemical changes

Question 4

who measured mass before and after a chemical reaction

Answer 4

Antoine Lavoisier

Question 5

the fact that matter isn’t created or destroyed in any chemical or physcial change

Answer 5

law of conservation of mass

Question 6

the substances you start with

Answer 6

reactants

Question 7

the substances that are formed at the end

Answer 7

products

Question 8

how are reactants written in a chemical equation

Answer 8

written on the left followed by an arrow that means yeilds or produces

Question 9

what is written on the right side of a chemical equation

Answer 9

products

Question 10

what are evidence of chemical changes

Answer 10

a change in chemical or physical properties and a change in energy

Question 11

what are some changes in properties that can result when new substances form

Answer 11

forming a precipitate, gas production, and a color change

Question 12

the ability to do work or cause change

Answer 12

energy

Question 13

the measure of the average motion energy in particles of energy

Answer 13

temperature

Question 14

what does it mean when particles move fast

Answer 14

greater energy and temperature

Question 15

the total energy of all the particles in an object

Answer 15

thermal energy

Question 16

what are the 2 major factors to compare thermal energy of substances

Answer 16

the amount of matter in an object and the temperature of the substance

Question 17

energy is released, usually as heat

Answer 17

exothermic reaction

Question 18

example of exothermic reaction

Answer 18

oxygen and fuels that produce fire

Question 19

absorb energy from nearby matter which can cause the surroundings to become cooler

Answer 19

endothermic reaction

Question 20

example of an endothermic reaction

Answer 20

snapping an ice pack

Question 21

when do chemical changes occur

Answer 21

when bonds between atoms break and new bonds form

Question 22

what do you need to break bonds

Answer 22

energy

Question 23

what does forming bonds cause

Answer 23

releasing energy

Question 24

the minimum amount of energy needed to start a chemical reaction

Answer 24

activation energy

Question 25

what do all chemical reactions need to get started

Answer 25

a certain amount of activation energy

Question 26

what happens after a few molecules react

Answer 26

the rest of the molecules will react very quickly

Question 27

where the reaction takes place could be open or close

Answer 27

system

Question 28

example of a system

Answer 28

beaker

Question 29

what is chemistry the study of

Answer 29

matter

Question 30

what are 3 examples of a physical property

Answer 30

magnetism,shininess, color

Question 31

what are 3 examples of a chemical property

Answer 31

ability to rush, tarnish, and burn

Question 32

PP, PC, CP, CC? DENSITY

Answer 32

PP

Question 33

PP, PC, CP, CC HALF AN APPLE TURNING BROWN OVER TIME

Answer 33

CC

Question 34

PP, PC, CP, CC PAPER BURNING

Answer 34

PC

Question 35

PP, PC, CP, CC BLENDING A SMOOTHIE

Answer 35

PC

Question 36

PP, PC, CP, CC MELTING POINT

Answer 36

PC

Question 37

PP, PC, CP, CC ABILITY TO RUST

Answer 37

CP

Question 38

PP, PC, CP, CC SOLUBILITY

Answer 38

PP

Question 39

what two parts make up the nucleus of the atom

Answer 39

proton and nuetrons

Question 40

how is the law of conservation of mass true on a closed system

Answer 40

since no atoms can escape

Question 41

how is the law of conservation of mass true on a open system

Answer 41

since the number and type of atoms are the same

Question 42

example of a heterogeneous mixture

Answer 42

vegetable soup

Question 43

example of a homogeneous mixture

Answer 43

blending a smoothie

Question 44

what are evidences of a chemical change

Answer 44

changes in energy and physical or chemical properties

Question 45

increases temp

Answer 45

exothermic

Question 46

the reactants have a higher total potential energy than the products

Answer 46

exothermic

Question 47

the energy released is greater than the energy absorbed

Answer 47

exothermic

Question 48

decreases temp

Answer 48

endothermic

Question 49

the products have a higher total potential energy then the reactants

Answer 49

endothermic

Question 50

the energy absorbed is greater than the energy released

Answer 50

endothermic

Question 51

the minimum amount of energy needed to start a chemical reaction

Answer 51

activation energy

Question 52

substances you start with

Answer 52

reactants

Question 53

the new substances that are formed at the end

Answer 53

products

Question 54

for catalyst how do you increase the rate of a reaction

Answer 54

lowering the activation energy required

Question 55

for catalyst how do you decrease the rate of a reaction

Answer 55

increasing the activation energy required

Question 56

for inhibitor how do you decrease the rate of a reaction

Answer 56

increase the amount of inhibitors

Question 57

for inhibitor how do you increase the rate of a reaction

Answer 57

decreasing the amount of inhibitors

Question 58

formula for density

Answer 58

D=M/V