chapter 7 (model of matter - particulate nature of matter)

Question 1

arrangement of particles [solid, liquid, gas]

Answer 1

1) solid
- packed very close together
- orderly/fixed pattern
- little space between particles
2) liquid
- packed closely together
- disorderly pattern
- slightly more space between particles [compared to solid]
3) gas
- far apart from each other
- disorderly pattern
- more space between particles

Question 2

movement of particles

Answer 2

1) solid
- unable to move freely
- vibrate in their fixed positions
2) liquid
- able to slide past one another
- moves throughout the liquid
3) gas
- move about randomly, freely and at high speeds

Question 3

expansion

Answer 3

-solid gains heat and expands [becomes bigger]
process :
-particles gain energy and vibrate more vigorously –> particles move slightly further apart from e/o
-volume of matter increases but mass and size stay the same (because the size and weight of the particles did not change)

Question 4

contraction

Answer 4

-solid loses heat and contracts [becomes smaller]
process :
-particles lose energy and vibrate less vigorously –> particles move closer to e/o
-volume of matter decreases but mass and size stay the same (because the size and weight of the particles did not change)

Question 5

properties of solid

Answer 5

1) shape
- fixed (bc they cannot move about freely/only vibrate at fixed positions)
2) volume
- fixed (bc of very strong forces of attraction that hold the particles close to e/o at all times)
3) density [mass over volume]
- very high density (bc particles are closely packed together, there is a large no. in a unit volume
4) compressibility
- cannot be compressed (bc particles are very closely packed, so there is little space between them)

Question 6

properties of liquid

Answer 6

1) shape
- not fixed (bc particles are not held at fixed positions, so they can move about more freely throughout the liquid by sliding against one another)
2) volume
- fixed (bc strong forces of attraction, particles are closely packed hence, occupy a fixed amount of space)
3) density
- high density (bc the particles are closely packed together, thus there is a large no. in a unit volume)
4) compressibility
- cannot be compressed (bc particles are closely packed, so there is little space between them)

Question 7

properties of gas

Answer 7

1) shape
- not fixed (bc the particles are not held in fixed positions. they move about freely and rapidly in any direction)
2) volume
- not fixed (bc weak forces of attraction, particles are far apart from each other, hence do not occupy a fixed amount of space)
3) density
- low density (bc the particles are far apart, thus there is a small no. in a unit volume)
4) compressibility
- can be compressed (bc particles are far apart so there is a lot of space between them)