Definitions

Question 1

What is carbon dating?

Answer 1

It is the ratio of carbon 12:carbon 14 in a living/once living thing. Carbon 14 decreases once something has died - this is useful for old thing (not VERY old but not recent either).

Question 2

What is nuclear fusion/fission?

Answer 2

Fusion- 2 smaller nuclei join together to make one larger nucleus (sum of the binding energy of a smaller nuclei is smaller than the sum of larger nuclei)
Fission is the opposite.

Question 3

Moderator

Answer 3

slows down any fast neutrons for fission to occur (graphite or heavy water)

Question 4

Control rods

Answer 4

controls rate of reaction by absorbing any excess neutrons

Question 5

Fuel rods

Answer 5

contains the fuel (U-235)

Question 6

Isotropic

Answer 6

looks the same in every direction

Question 7

Homogenous

Answer 7

matter is distrubuted uniformly

Question 8

What is mass defect?

Answer 8

is the difference between the mass of a nucleus and the sum of the mass of its nucleons if they were seperated.

Question 9

Refraction

Answer 9

When a wave changes direction its speed changes; this happens when it enters a new medium. The frequency stays the same but the speed changes (sound waves speed up in denser materials but electromagnetic waves slow down). Therefore wavelength changes.

Question 10

Snells law

Answer 10

n*sinx = constant at a boundary

n1sinx1 = n2sinx2 rearrange to find

Question 10

Diffraction

Answer 10

Is the spreading out of a wave as it passes through a gap.

Question 11

Kirchoffs 1st Law

Answer 11

At any point in a circuit the current in is equal to the current out.

Question 12

Kirchoffs 2nd Law

Answer 12

In a closed loop the sum of the pds is equal to the total emf.

Question 13

Ultimate tensile strength

Answer 13

The maximum force an object can withstand before it breaks.

Question 14

Kinetic Theory Model - particles

Answer 14

Solids- When graph is increasing in solid state then particles are close together and vibrate in fixed lattice positions. As temp increases space between particles to increase.
Liquids - When graph is increasing in liquid state particles vibrate more and are further away as temp continues to rise.

Question 15

Kinetic Theory Model - energies

Answer 15

When a substance is heated, but is in the same state (gradient) , the kinetic energy increases but the potential energy remains the same. When a substance changes state (flat gradient) the potential energy increases, but the kinetic energy remains the same.

Question 16

Internal energy

Answer 16

Sum of the random kinetic and potential energies of each molecule added together.

Question 17

What eq to use when you have 2 pressures, change in temp, 1 volume and want to find out the other volume.

Answer 17

pV/T = pV/T
sub in values and rearrange.

Question 18

Assumptions of kinetic theory of gases

Answer 18

• Forces are negligible except during collisions
• Collisions are perfectly elastic
• Particles occupy negligible volume compared to volume of gas
• Lots of particles move in random motion