chapter 7

Question 1

brownian motion

Answer 1

random movement of microscopic particles suspended in a liquid/gas

Question 2

what are the spaces between particles occupied by

Answer 2

not. by matter, but vacuum

Question 3

matter definition

Answer 3

anything that has mass and takes up space

Question 4

solid properties

Answer 4

• definite volume
• definite shape
• cannot be compressed

Question 5

liquid properties

Answer 5

• definite volume
• no definite shape
• cannot be compressed

Question 6

gas properties

Answer 6

• no definite volume
• no definite shape
• can be compressed

Question 7

why do solids have definite volume/shape

Answer 7

• particles are very closely packed in an orderly matter
• vibrate about the fixed position

Question 8

why cant solids be compressed

Answer 8

• there is very little space between particles for them to move closer togethter

Question 9

how are solids particles held together

Answer 9

• held by very strong forces of attraction

Question 10

why do liquid have definite volume but not definite shape

Answer 10

• particles are closely packed in a disorderly manner
• move randomly and slide past another

Question 11

why cant liquid be compressed

Answer 11

• particles closely packed but are further apart than in an solid
• little space between particles for them to move closer together

Question 12

how are liquid particles held together

Answer 12

• strong forces of attraction

Question 13

why dont gases have defenite volume/defenite shape

Answer 13

• particles are far apart and arranged in a disorderly manner
• move randomly and quickly

Question 14

why can gases by compressed

Answer 14

• lots of space between particles to move closer together

Question 15

how are gases held together

Answer 15

• weak forces of attraction

Question 16

expansion (solids)

Answer 16

• particles gain energy and vibrate more vigorously about the fixed positions
• increased distance between particles
• causes volume of substance to increase

Question 17

contraction (solids)

Answer 17

• particles lose energy and vibrate less vigorously about their fixed positions
• decreases distance between positions
• volume of substance decreases

Question 18

conservation of mass

Answer 18

• number and size of particles stay the smae

Question 19

change in state

Answer 19

• melting
• boiling
• freezing
• condensation

Question 20

melting

Answer 20

solid changes into a liquid without a change in temperature

Question 21

boiling

Answer 21

liquid changes into a gas without a change in temperature

Question 22

melting explained

Answer 22

• solid is heated, particles gain energy
• vibrate faster in fixed position
• gain enough energy to overcome very strong forces of attraction
• solid melts -> liquids

Question 23

boiling explained

Answer 23

• liquid is heated, particles gain energy
• move faster and further apart from one another
• gain enough energy to overcome strong forces of attraction
• liquid boils -> gas

Question 24

condensation explained

Answer 24

• gas is cooled, particles lose energy and move slower
• particles pull close to another by forces of attraction
• gas condenses -> liquid

Question 25

freezing explained

Answer 25

- liquid is cooled, particles lose energy and move slower - causes particles to be pulled much closer to another by forces of attraction between them - particles are eventually held in fixed positions - liquid freezes -> solid

Question 26

diffusion

Answer 26

net movement of particles from a region of higher concentration to a region of lower concentration

Question 27

diffusion explained

Answer 27

1) drop of ink is added into a beaker of water 2) high concentration of ink particles at the bottom of the water 3) ink particles move randomly in various directions until the concentration of the ink particles throughout the beaker in uniform