Particle Theory

Question 1

what is density?

Answer 1

the measure of compactness of a substance. it relates to the mass of a substance and how much space it takes.

Question 2

how to calculate density?

Answer 2

density = mass (kg/g) / volume (m²/cm²)

Question 3

what is specific heat capacity?

Answer 3

The amount of energy needed to raise the temperature of 1 kg of substance by 1°C.

Question 4

how to calculate heat energy in joules?

Answer 4

Q (specific heat capacity) = M (kg) × C (specific heat capacity) × ΔT (temperature change)

Question 5

give an example of substances with different densities

Answer 5

sponge - low density, compressible, high absorbability
brick - high density, low compressibility

Question 6

what is 1m³ in cm

Answer 6

1 000 000 cm

Question 7

what is 1m² in cm

Answer 7

100 000 cm

Question 8

how to find volume of regular shapes?

Answer 8

area of cross section × length

Question 9

how to find area of irregular shapes?

Answer 9

eureka can experiement

Question 10

how to carry out eureka can experiment

Answer 10

Measure the mass: Use a balance to measure the mass of the object
Fill the can: Fill the Eureka can with water to a level just below the spout
Insert the object: Carefully lower the object into the can
Collect the displaced water: Place an empty measuring cylinder under the spout to collect the water that is displaced
Measure the displaced water: Measure the volume of the water that was displaced
Calculate the density: Use the measurements to calculate the density of the object

Question 11

forces of attraction in a solid

Answer 11

strong forces of attraction which hold particles close together and in a fixed, id arrangement. do not have much energy so only vibrate in their fixed positions (vibrational energy)

Question 12

forces of attraction liquid

Answer 12

weaker forces of attraction between particles, meaning they are close together but can move and form irregular arrangements. more energy than solid particles and can move randomly at slow speeds.

Question 13

forces of attraction gas

Answer 13

no forces of attraction between particles. more energy than solids and liquid and can move at high speeds in random directions - random motion.

Question 14

what does density do as the volume decreases?

Answer 14

density increases as volume decreases

Question 15

what happens to density as compressibility decreases?

Answer 15

density increases as compressibility decreases

Question 16

what is internal energy?

Answer 16

amount of energy particles have and the state of substance depends on the temperature

Question 17

what do different substances require?

Answer 17

different amounts of energy to change state

Question 18

why do substances change state?

Answer 18

if the substances are heated enough, the particles will have enough energy in their Kinetic Energy store to break the bonds holding them together resulting in a change of state

Question 19

what is specific heat latency?

Answer 19

the energy needed to change the state of a substance

Question 20

difference between specific heat latency and specific heat capacity

Answer 20

specific heat capacity is the energy needed to change the temperature of a substance, while specific latent heat is the energy needed to change the state of a substance