Physics Definitions

Can't predict which nucleus will decay and when.

The probability that one atom will decay per unit time.

The time taken for the decay rate (activity) to fall to half its original value.

The number of nuclei of the isotope that disintergrate per second.

OR,

The rate of change of the number of nuclei of the isotope.

(1 Bequerel = 1 Disintergration per second)

Atoms of the same element that have the same number of protons but a different number of neutrons.

u, is defined as one twelfth of the mass of one atom of carbon-12.

The energy required to completely separate the nucleus into its individual nucleons.

The mass of a nucleus is always less than the total mass of its constituent nucleons. This difference is called the Mass Defect.

Any nucleus has a mass defect which, when concerted to its energy equivalent, is equal to the binding energy of that nucleus.

Occurs when a large nucleus, such as that of Uranium, splits into two much smaller nuclei.

Takes place when two nuclei combine to form a bigger nucleus.

A material that slows down fast neutrons (produced by fission process) without absorbing them.

Suitable materials: Carbon in the form of Graphite, Heavy Water (Deuterium Oxide).

Absorb surplus neutrons before they cause further fission.

The heat energy, in joules, required to increase the temperature of 1kg of that substance by 1K.

The heat required to change the state of 1kg of the material from solid to liquid without a change in termperature.

The heat required to change the state of 1kg if the material from liquid to vapour (gas) without a change in temperature.

For a fixed mass of gas at constant temperature, the pressure is inversely proportional to the volume.

For a fixed mass of gas at a constant pressure, the volume is directly proportional to the absolute temperature.

For a fixed mass of gas at constant volume, the pressure is directly proportional to the absolute temperature.