Atomic Structure

Proton

subatomic particles carrying a charge equal to but opposite to that of an electron

Neutron

subatomic particle that has a mass nearly equal to that of a proton but carries no charge

Isotopes

atoms with the same number of protons but different numbers of neutrons

Mass number

identifies each isotope of an element and is the sum of the atomic number (or number of protons) and neutrons in the nucleus.

Radioactivity

When substances emit radiation

Radiation

Rays and partcles emitted by the atoms

Radioactive decay

When unstable nuclei loses energy by emitting radiation in a spontaneous process

Types of radiation

1. Alpha radiation

2. Beta radiation

3. Gamma radiation

What determines an atom’s stability?

The ratio of neutrons to protons

Atoms containing too many or too few neutrons are unstable and lose energy as they decay to form a stable nucleus.

Alpha radiation

involves alpha particles containing two protons and two neutrons and thus has a 2+ charge (don’t have electrons)

Alpha particles are

negatively attracted to the negatively charged plate

Alpha particles are equivalent to

helium-4 nucleus

Beta radiation

Involves beta particles which are electrons with a charge of 1- and no mass

Process of beta radiation

Electrons arent emitted from the atom shells

One of the atom’s neutron’s decay into a proton and electron

The proton stays in the nucleus and the electron is emitted out at a high speed

Gammy rays

not particles, waves of electromagnetic radiation

(lighters, light)

Charge of gammy rays

No mass/charge

When does this radiation happen?

After beta radiation as a way to get rid of the extra energy in the nucleus