Introduction to Nuclear Chemistry

Isotopes

Particles of the same elements having different number of neutrons

Nucleons

Particles in the nucleus, i.e, protons, and neutrons

Alpha particle

A helium nucleus possessing a positive charge

Beta particle

Basically an electron, possessing a negative charge

Positron

A positive electron

Gamma ray

Not a particle, but an electromagnetic wave. Something emitted during nuclear reactions

Nucleons

__________ are being exchanged in nuclear reactions

Electrons

______ are being exchanged in chemical reactions from one compound/atom to the other to form other compounds

Mass no.

#of protons + #of neutrons = ?

Atomic no.

#of protons

Neutrons

Mass no. - Atomic no.

Electrons

If the atom is neutral, the no. of electrons equals the no. of protons

• Alpha decay / emission

• Beta decay / emission

• Positron decay / emission

• Electron capture

Types of Nuclear Reactions

Alpha decay / emission

Nuclear reaction wherein an alpha particle is released.

Alpha decay / emission

Alpha particle is released, it’s also part of the product

Beta decay / emission

Nuclear reaction wherein beta particles is released

Positron decay / emission

Nuclear reaction positron is released

Electron capture

Beta particle is absorbed by the reactant; part of the reactants

Nuclear Stability

Refers to how likely an atomic nucleus is to stay together without changing or breaking apart

When it has a balanced ratio of protons to neutrons, which keeps it from undergoing radioactive decay

When is a nucleus considered stable?

It may undergo radioactive decay to become more stable.

What happens if a nucleus is not stable?

To reach a more stable state.

Why do unstable nuclei release particles or energy?

It is the process where an unstable nucleus releases radiation to become more stable.

What is radioactive decay?

Because the nucleus is unstable and wants to become balanced.

Why does radioactive decay happen?

By N/Z ratio (N = no. of neutrons ; Z = atomic no.)

How is nuclear stability determined?

Bismuth, alpha

Heavy elements: All elements beyond _______ are unstable, and mostly undergo ______ decay

lose, decrease

For heavy elements, they want to ______ protons, their atomic no. _______ up to a point that they reach a stable state.

calcium, 1

Light elements: up to ______, the stable isotopes have a ratio N/Z = ?

beta

If there are more neutrons over protons, then ______ decay is probable

positron

If there are more protons over neutrons, then ______ decay is probable

It is the process where one element changes into another by changing the number of protons in its nucleus.

What is nuclear transmutation?

Through radioactive decay, where unstable atoms change into different elements.

How does nuclear transmutation happen naturally?

It is when scientists cause an element to change into another by bombarding its nucleus with particles.

What is artificial transmutation?

It helps create new elements (beyond uranium) or useful isotopes in labs or reactors.

Why is artificial transmutation useful?

Nuclear Fission

It is when a large atomic nucleus splits into smaller nuclei, releasing energy.

What causes nuclear fission to happen?

It can happen when a neutron hits a heavy nucleus like uranium or plutonium.

Nuclear Fusion

It is when two small nuclei join together to form a bigger nucleus, releasing energy.

In stars, including the sun.

Where does nuclear fusion happen naturally?