chapter 2

Question 1

whats matter

Answer 1

anything with mass that takes space {i.e. water, wood, and plastic bags}

Question 2

pure substance

Answer 2

has a fixed or definite compostion composed of 1 type of atom

Question 3

mixtures

Answer 3

has two or more different substances that are physically mixed NOT CHEMICALLY COMBINED

Question 4

compound

Answer 4

composed of 2 or more elements always combined in same proportion (a definite ratio) I.e. hydrogen peroxide (H2O2)

Question 5

elements

Answer 5

a pure substance only has 1 type of material ie copper cu

Question 6

can mixtures be seperated

Answer 6

yes by physical methods i.e. spaghetti and water via strainer

Question 7

how are mixtures of liquids + solids seperated

Answer 7

by filtration or using chromatography paper as they travel at diff rates up the surface you can actually see them

Question 8

what are homogenous mixs

Answer 8

the comp is uniform throughout and you cant tell the different parts in the mix

Question 9

examples of homogenous mixtures

Answer 9

scuba breathing mixtures i.e. nitrox (oxygen and nitrogen gases)

Question 10

heterogenous mixtures

Answer 10

comp varies from one part of the mix to another diff parts of mix are visible i.e. water and copper

Question 11

which is a pure substance or a mixture
a. pasta and tomato sauce
b. aluminum foil
c. helium
d. air

Answer 11

a. mix
b.pure substance
c. pure substance
d. mix

Question 12

3 states of matter

Answer 12

solid, liquid, or gas

Question 13

solids have

Answer 13

definite shape, volume, particles held close together by strong attractive forces , particles arranged in rigid pattern, can only vibrate slowly in fixed positions i.e. amethyst

Question 14

liquids have

Answer 14

definite volume but not definite shape, have same shape as container, particles that move slowly in random directions

Question 15

gases have

Answer 15

indefinite shape, volume, same shape and volume as container, particles far apert, move at high speeds, have littles attraction to one another

Question 16

physical properties

Answer 16

characteristics observed or measured without changing substance identity i.e. shape, physical state, boiling/freezing points, density, color of substance

Question 17

physical properties of copper

Answer 17

reddish orange color, shiny, excellent conductor of heat and electricity, solid at 25 degrees Celsius, melting point 1083 degrees Celsius, boiling point 2567 degrees Celsius.

Question 18

physical change

Answer 18

matter going physical state of change but composition remains constant i.e. water had 3 states ice, water, steam

Question 19

physical changes also can change physical appearance

Answer 19

i.e. salt is dissolved in water salt crystals no longer visible but can reform with evaporation

Question 20

chemical properties

Answer 20

chemical prop descr. ability of a sub. to interact w/ other sub. and to change into a new sub.

Question 21

chemical change

Answer 21

when this occurs orig. sub. turned into 1 or more new sub. w/ new physical and chem prop.

Question 22

chem change what happens

Answer 22

new comp, new physical properties, new chemical prop i.e. iron nails corrode in water and a new sub forms called rust

Question 23

defibriliater

Answer 23

provides energy to restore bodies cardiac function

Question 24

energy is

Answer 24

bodies ability to do work can be kinetic or potential

Question 25

kinetic energy

Answer 25

energy of motion

Question 26

potential energy is

Answer 26

determined by the positions of an objects or its chemical comp.

Question 27

identify the energy in each example as potential or kinetic? a. rollerblading b. a peanut butter and jelly sandwhich c. mowing the lawn d. gas in the gas tank

Answer 27

a. kinetic b. potential c. kinetic d. potential

Question 28

heat is

Answer 28

energy associated with the motion of particles and the faster they move the greater the heat or thermal energy of the substance si unit of energy and work is the joule (j) 1 kj = 1000 j

Question 29

carbs

Answer 29

when carbs are exhausted fats and then proteins are used for energy

Question 30

calorimeters measure energy valies

Answer 30

they determine the energy value for the food

Question 31

changes of state are

Answer 31

melting, freezing, boiling, condensation, and sublimation and deposition.

Question 32

change of state happens when

Answer 32

it is converted from 1 state to another at a constant temp

Question 33

melting is

Answer 33

when it changes from a solid to liquid at its melting point (mp)

Question 34

freezing is

Answer 34

when it changes from a liquid to a solid at its freezing point (fp)

Question 35

sublimination

Answer 35

the particles in the surface of a solid change directly to a gas without going through the liquid state no change in temp

Question 36

deposition

Answer 36

reverse of sublimination and gas particles change directly to a solid dry ice is an ex

Question 37

evaporation

Answer 37

happens when water molecules gain sufficient energy to escape the liquid surface and enter gas

Question 38

boiling point

Answer 38

molecules have enough energy to overcome their attractive forces and become a gas

Question 39

condensation

Answer 39

water vapor is converted to a liquid as the water molecules lose kinetic energy and slow down occurs at same temp as boiling but heat is removed

Question 40

vaporization and condensation are

Answer 40

reversible processes