Chemistry Unit 4 – Nuclear Chemistry

A, X

a nuclear particle

1/12 the mass of a carbon 12 atom

m in e=mc^2

Works inside the nucleus, keeps it together

E in E=mc^2, the energy released when a nucleus is formed from separate nucleons

take 2 small nuclei, put together

A = #p+#n
the total number of nucleons

it is converted into energy (E=mc^2)

slightly less than the sum of its parts

an atom is referred to this in nuclear chemistry

The mass defect is caused by the conversion of mass to energy upon formation of the nucleus

the energy released when a nucleus is formed from nucleons, the amount of energy needed to break apart the nucleus

the stable nuclei cluster over a range of neutron -proton ratios

a reaction that affects the nucleus of an atom

a change in the identity of a nucleus as a result of a change in the number of its protons, one element into another

the spontaneous disintegration of a nucleus into a slightly lighter nucleus, accompanied by emission of particles, electromagnetic radiation, or both

the radiation that exposed the plate, and it is particles or electromagnetic radiation emitted from the nucleus during radioactive decay

two protons and two neutrons bonded together and is emitted from the nucleus during some kinds of radioactive decay
(emission)

nuclides above stability band are unstable bc their neutron/proton ratio is too large – to decrease neutrons, a neutron can be converted into proton and an electron. The beta particle is an electron emitted from the nucleus during some kids of radioactive decay
(emission)
high energy electron
beta decay results in increase in atomic number

Nuclides below band of stability- neutron proton ratios too small – must decrease number of protons – proton can be turned into a neutron by emitting a positron. A positron is a particle that has the same mass as an electron, but has a positive charge and is emitted from the nucleus during some kinds of radioactive decay
(emission)
no mass #

for nuclides that have a neutron proton ratio that is too small is electron capture – the inner orbital electron is captured by the nucleus (absorbed by nucleus) of its own atom
Inner orbital electron combines with a proton, and a neutron is formed

high energy electromagnetic waves emitted from a nucleus as it changes from an excited state to a ground energy state, nuclear radiation similar to x ray

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

a series of radioactive nuclides produced by successive radioactive decay until a stable nuclide is reached

The heaviest nuclide of each decay series

the nuclides produces by the decay of the parent nuclide

bombardment of nuclei with charged and uncharged particles

elements with more than 92 protons in their nuclei – if #p changes, then element ID changes!

the process by which the approx age of an object is determined based on the amount of certain radioactive nuclides present

a very heavy nucleus splits into more stable nucli of intermediate mass

a reaction in which the material that starts the reaction is also one of the products and can start another reaction

the minimum amount of nuclide that provides the number of neutrons needed to sustain a chain reaction – amount of material needed to produce a self-sustaining reaction

radiation-absorbing material that is used to decrease exposure to radiation, espeially gamm rays, from nuclear reactors

neutron obsorbing rods that help control the reaction by limiting the number of free neutrons

used to slow down the fast neutrons produced by fission

low-mass nuclei combine to form a heavier, more stable nucleus

Depends on the N/Z ratio, for small atoms it should be 1, for large atoms it should be 1.5

top secret project to build nuclear fission bombs

“little boy”, long/skinny, uranium

“Fat man” bomb, plutonium implosion

nuclear disintigrations per unit time, k

the neutron to proton ratio

steam

H

Robert Oppenheimer