Physics - U1T2 Ionizing Radiation and Nuclear Reactions

atomic number

number of protons that it contains which determines the element

isotopes

atoms of the same element with a different number of neutrons

atomic mass number

no protons + no neutrons

ionic charge

no protons - no electrons

nuclear reactions

involve a change in the number and types of subatomic particles present, and change the type of atoms present.

einsteins formula

E=m.c²

conservation of mass number

total mass numbers of the reactants is equal to the total mass number of the products

atomic number

number of protons in an atom of that elements

conservation of atomic number

the total atomic numbers of the reactants must equal the total atomic number of the products

alpha decay

produces a Helium-4 nucleus. a form of ionizing radiation, not dangerous.

beta decay

produces an electron which is emitted from the nucleus when a neutrons turns into a proton and electron. ionizing radiation and high penetration.

gamma decay

produces a photon to destabilize the nucleus. not made up of charged particles

positron decay

produces an anti-electron which is created in the nucleus when a proton is transformed into a neutron.

neutrinos

tiny subatomic particles that rarely interact with other particles with no charge.

nuclear fission

when a heavy nucleus divides into 2 lighter nuclei .

decay series

when a radioactive isotope decays into another isotope that is also radioactive. continues decaying until stable isotope is reached.

amu

atomic mass unit

mass defect

the difference in mass between the atom and it’s parts. caused by the conversion of mass into energy according to einsteins formula

binding energy

energy that corresponds to the mass defect of the nucleus since it corresponds to the amount of energy which must be put into the nucleus to overcome the binding forces between the nucleons.

MeV

Mega Electron Volt

binding energy per nucleon

binding energy is shared by all nucleons - divide binding energy by number of nucleons

the most stable nucleons have

high binding energy per nucleon

nuclear fusion

when 2 light nuclei combine to form a heavier nucleus

atomic number symbol

Z

mass number symbol

A

ionic charge symbol

Q

thermal equilibrium

the condition in which the particles of 2 or more objects in contact have the same temperature and average kinetic energy as each other

work done (W)

the product of the force acting on it and the component of the objects displacement in the direction of that force

energy

the property that an object has which enables it to do work

kinetic energy

energy an object has as a result of its velocity

gpe

energy an object has as a result of its position in a gravitational field

power

the rate at which work is done by a force

efficiency

ration of work out to work in