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Question 1

Describe the history of the atom

Answer 1

1803 John Dalton said all matter was made up of atoms which were solid spheres
1897 JJ Thompson said there were smaller negatively charged particles called electrons scattered about the atom like plums in a plum pudding
1909 Rutherford conducted the gold foil experiment which lead to the discovery of the nucleus
1913- Bohr said that electrons can only exist on fixed energy levels

Question 2

Density=

Answer 2

Density = mass / volume

Question 3

How do you measure the density of an object?

Answer 3

1) measure it’s mass using scales
2) gently lower into a eureka beaker which is filled up to just below the spout
3) measure the volume of the displaced water
4) use the equation to find its density

Question 4

Explain the difference between solids, liquids and gases

Answer 4

Solids- strong forces of attraction between particles so they have a fixed regular formation. Particles don’t have much energy in their kinetic energy stores so they can only vibrate around a fixed point
Liquid- weaker forces of attraction between particles so they are free to move past each other. Liquids have more energy in their kinetic energy stores so they are able to move in random directions at low speeds
Gas- little forces of attraction between particles and have more energy in their kinetic energy stores so they can move quickly in random directions

Question 5

Why does a substances density change between states

Answer 5

The mass doesn’t change because it’s the mass of the particles and the particles are only rearranged where as the volume does change because the particles are closer/ further away in different states and because density is mass x volume the density also changes

Question 6

What is specific heat capacity

Answer 6

The specific heat capacity of a substance is the amount of energy required to raise the temperature of 1 kg by 1 degree

Question 7

Relative mass of electron

Answer 7

Relative mass of electron is 0.0005

Question 8

Weight of an atom

Answer 8

Weight of an atom is 1x 10^-23g

Question 9

Diameter of a nucleus

Answer 9

Diameter of a nucleus is 1x 10^-15

Question 10

What is the definition of specific heat capacity

Answer 10

Specific heat capacity is the amount of energy required to raise the temperature of 1kg of a substance by 1 degree

Question 11

What is the definition of specific latent heat?

Answer 11

Specific Latent heat is the amount of energy required for 1kg of a substance to change state

Question 12

PRACTICAL measuring specific heat capacity

Answer 12

1) measure the mass of the substance
2) set up a power pack, joulemeter and electric heater
3) put the substance in a thermal cup with a thermometer
4) measure a starting temperature
5) turn on the power until the temperature goes up by a set amount (e.g. 10 / 20 degrees)
6) measure the reading on the joulemeter
7) use SHC= change in thermal enefgy/ mass x change in temp

Question 13

Why does a balloon contract

Answer 13

Because the pressure inside the balloon of the particles exerting force on the walls is less than the outside pressure

Question 14

Why does increasing the temperature increase gas pressure

?

Answer 14

Because the heat energy is stored in the particles kinetic energy stores. And KE= 1/2 x mass x velocity2 and the mass doesn’t change so therefore the speed must increase which increases the gas pressure because there are more collisions per minute

Question 15

How does volume effect pressure?

Answer 15

Volume is inversely proportional to pressure

Question 16

Why does work done on gases increase the temperature?

Answer 16

Work dome on gases increases the temperature because the force on the gas such as in a bike pump makes the gas do work against that force which transfer kinetic energy to the particles which increases the temperature

Question 17

Where is the most atmospherical pressure and why

Answer 17

There is most atmospherical pressure the lower you are because there is more air above you so the weight of the air causes more pressure

Question 18

Where is the highest density of the atmosphere

Answer 18

The highest density of the atmosphere I’d at sea level because there is more air above and the weight of the air compresses the air below

Question 19

Why does liquid pressure increase with depth

Answer 19

Liquid pressure increases with depth because the weight of the column of liquid above it increases the pressure

Question 20

At what depth do you experience another atmosphere of liquid pressure?

Answer 20

At 10m depth you experience another atmosphere of liquid pressure

Question 21

How do you make a steel boat float?

Answer 21

To make a steel boat float the combined density of the steel and the air inside must be less than water