P1-Matter

Question 1

1. )a.) Describe Rutherford’s gold foil experiment

b. ) How did the results of this experiment disagree with the Thomson model of the atom.

Answer 1

a. ) Rutherford fired positive alpha particles at an extremely thin gold foil sheet.
b. ) Thomson model was a positive pudding with negative currents, because the charge in the model is all spread out it was suggested that the alpha particles would go straight through or be slightly deflected, however, some of the particles were deflected straight back suggesting the need for a new structure to be put in place.

Question 2

2.) How did Bhor’s model of the atom differ to Ruderfords

Answer 2

2.) Rutherford suggested a positive nucleus surrounded by a cloud of electrons where as Neil’s Bohr suggested that electrons were kept in shells and those shells have a fixed energy and orbit.

Question 3

3. )a.) What is the size of an atoms diameter
   b. ) What is the weight of an atom
   c. ) What is the size of the atomic radius

Answer 3

a. ) 1x10^-10 m
b. ) 1x10^-23 g
c. ) 1x10^-15 m

Question 4

4.) What is density and how is it calculated?

Answer 4

4.) Density is the compactness of a substance it relates to the mass and how much room it takes up.
Density (kg/m^3)= Mass (kg)/ Volume (m^3)

Question 5

5.) Describe solids, liquids and gases in terms of the movements of their particles.

Answer 5

Solids: There particles are compacted together and the particle vibrate about fixed positions
Liquids: There particles can move over each other they move in random directions at low speeds and are relatively close together more energy than solids.
Gases: There particles move at high speeds in random directions and are free to move as they have more energy.

Question 6

6.) What happens to the mass of a substance when it changes state ?

Answer 6

It stays the same.

Question 7

7.) What is the relationship between temperature and the energy in the kinetic energy store of the particles in a substance?

Answer 7

The temperature (or thermal energy) of a substance is controlled by the amount of kinetic energy in that substance particles so the more thermal energy, the more kinetic energy the particles in that substance has.

Question 8

8.) What is the specific heat capacity of a substance?

Answer 8

The energy required to raise 1 kg of a substance by 1°C

Question 9

9.) Describe an experiment to find the specific heat capacity of a substance.

Answer 9

Weigh the substance on a mass balance. A joule-meter (or an ammeter and a voltmeter(a timer will also be needed)) is connected to a heater to see how much energy it takes to heat a substance. The substance is placed in a polystyrene cup with the heater and thermometer in it. Make sure the joule meter reads 0 before you start and look at the thermometer once the substance has changed by 10°C see how much energy was required. Plug it into the equation to find the SHC.

Question 10

10.) A gas is cooled, until it becomes a liquid and eventually turns to a solid. Sketch a graph showing how the temperature of the substance changes over time, including labels to show the boiling point and the melting point and changes of state.

Answer 10

Insert image.

Question 11

11. ) What is meant by:
    a. ) the specific latent heat of fusion?
    b. ) the specific latent heat of vaporisation?

Answer 11

a. ) The changing of state from solid to a liquid and visa versa
b. ) The changing of state between a liquid and a gas.

Question 12

12.) What happens to the pressure of a gas in a sealed container of a fixed volume when heated?

Answer 12

The pressure increases if you heat it up as the particles gain more energy so they collide with the walls and other particles more frequently.

Question 13

13.) What is the relationship between pressure and volume at a constant temperature.

Answer 13

Constant= volume x pressure

As the volume increases the pressure decreases, as the volume decreases the pressure increases.

Question 14

14.) Describe how a change in external pressure can lead to a change in volume of a gas sealed inside a container.

Answer 14

If the external pressure increases the volume of the container will decrease only if the internal force is less than the external force. If the internal force is greater than the external force the volume will increase this is so when the external pressure decreases.

Question 15

15.) What is atmospheric pressure?

Answer 15

It is the pressure of the earths air which is naturally exerted on us.

Question 16

16.) How and why does atmospheric pressure change with height?

Answer 16

The higher you go the less pressure because there are less particles on top of you and less atmosphere so less force is felt.
The lower the more pressure as there is more atmosphere above you so more weight and particles.

Question 17

17.) How do you calculate the pressure at different depths in a liquid.

Answer 17

Pressure due to a column of a liquid=

height of the column x density of the liquid x gravity

Question 18

18.) In what conditions will an object float?

Answer 18

If the upthrust acting on the object is the same as the weight of fluid displaced( the weight of the object), the object has to be less dense than the liquid or have a greater surface area.