Nuclear Chemistry

What is nuclear chemistry?

Nuclear chemistry involves changes in the nucleus

Only ____________ & _____________ are involved nucleus

protons, nuetrons

Transmutation:

when the atomic nucleus of one element is changed into the nucleus of a different one

Elements with a nucleus containing 83 protons or more are considered…

Radioactive (radioisotope)

If something is radioactive (radioisotope)…it

does not have stable isotopes

93 protons or more is considered…

radioactive and synthetic

synthetic

not found in nature

Stability is determined by…

the ratio of protons to neutrons

What is the ratio that is considered stable?

1:1

If the ratio is not 1:1, it is considered…

unstable

Is it possible that some isotopes of atoms under 83 protons are unstable and typically radioactive?

Yes

What are some examples that some isotopes of atoms under 83 protons are unstable?

14C vs. 12C

Radioactive nuclei are…

unstable

Since radioactive nuclei are unstable…they will _______ towards ________.

decay, stability

Since radioactive nuclei are unstable, they will decay towards stability, how will they do that?

by emitting alpha & beta particles, positrons, and/or gamma radiation

Gamma particles have the _________ penetrating power

greatest

Alpha particles have the ___________ penetrating power

weakest

If the arrow is pointing towards the positive, it is an…

alpha particle

If the arrow is not pointing to either positive and negative, is it a…

gamma ray

If the arrow is pointing towards the negative, it is an…

beta particle

When doing alpha decay, the nucleus ejects an a particle to which becomes a ___________ nucleus with _________ ______________ charge

smaller, less positive

What is the format of all decay questions:

Parent atom --> daughter atom + particle

When doing beta decay, the nucleus ejects a B particle and ________ it's nuclear charge by one (aka: ___________ atomic # by one)

increasing, increasing

Posotron emission

the production of a positron during the conversion of a proton to a neutron

Gamma

has no mass or charge

Which particle is always emitted with a or beta?

gamma

Gamma is the _______ destructive form of nuclear radiation (high energy particle)

most

What are the two different types of transmutation reactions?

Natural and artificial

Natural

Spontaneous disintegration (breakdown) of unstable nucleus yielding particles and/or energy

Natural has _____ reactant

one

Natural reaction consists of…

alpha, beta, and positron

Artificial

bombardment of nuclear particles (protons, neutrons, alpha particles) to the nucleus of an atom

Artificial has ________ reactants

two

Nuclear Fission

Occurs when large/heavy nucleus (like Uranium-235 or Plutonium-239) captures a neutron

Fission =

division

During nuclear fission, the large/heavy nucleus…

splits into two smaller particles

How much energy does nuclear fission produce?

Enormous amount of energy

Nuclear Fusion

Combining lighter nuclei to form heavier, more stable nuclei

Energy is ____________ as a _________ in both fusion and fission reactions

produced, product

Nuclear reactions convert matter/mass into…

energy

During nuclear reactions, mass…

is not conserved

During nuclear reactions, mass is not conserved; the total mass of the products is ________ then the total mass of the ______________.

less, reactants

Iconic formula (fusion)

E=mc^2

Half-Life

Measures the rate of radioactive decay…the time it takes for 1/2 of the atoms in a given sample of an element to decay

The shorter the half-life…

the less table it is

Half life is unaffected by __________ or ___________, only based on the nature of the nucleus

temperature, pressure

What are the four pieces of data for solving half-life problems

Half-life, starting material mass, final mass, and total decay time

Uses of radioisotopes

Can be used to trace a reaction

Radiation risks

Damage to normal cells/tissues, serious illness/death, mutations

When doing/using radioisotopes, you want it to have a _______ half life and be ________ eliminated from the body.

short, quickly

Use for 14C

Dating once living (organic organisms)

Use for 238U

Dating geological rock formations (U:Pb ratio)

Use for 131I

Thyroid issues

Use for 60Co

Radiation therapy for cancer

Use for 99Tc

Detection of brain tumors

Use for 32P

Fertilizer applications

Use for Gamma Irradiation

Kills bacteria on food to increase shelf life