Nuclear stability

What atoms have a ratio of 1:1 (neutrons to protons)?

Atoms with an atomic number of 1-20 should have an equal amount of protons and neutrons.

What atoms have a ratio over 1:1 but less than 1.5:1 ratio?

Atoms with an atomic number of 21-83 need more neutrons than protons.

Example of 21-83

Silver (Ag) → 47p+ and 61 n → 61/47 = 1.3

What atoms cannot have enough neutrons to make the nucleus stable?

Atoms with atomic # greater than 83 cannot have neutrons to make the nucleus stable so the protons will repel and the nucleus will break apart.

Example of over an atomic #83

Uranium → 92p+ 146 neutrons

Fission

splitting of a nucleus into fragments → releases large amounts of energy.

Fusion

combining of nuclei

Radioactive decay

spontaneous breakdown of a larger nuclei to a lighter/smaller nucleus. → electromagnetic radiation can be released.

Alpha emission

• more than 83 protons

• alpha particle: 2 protons and 2 neutrons bound together

• least dangerous

• element: 4,2 He

Beta emission

• too many neutrons (above the band of stability)

• neutrons spilts into a proton and an electron (beta particle)

• moderate danger

• 0, -1 e

Gamma emission

• high energy electromagnetic waves emitted from a nucleus as it changes.

• usually occurs with other types of decay

• most dangerous

• 0,0 and upside down banner

Half life

the time required for half of a radioactive nuclide to decay.