402 Atoms, isotopes and half life

Atomic structure, isotopes and radiotopes

Define a radioactive isotope

An atom with an unstable nucleus, that spontaneously decays and emit radiation until it becomes stable

Define an isotope

Are the same type of element with atoms which contain different numbers of neutrons

What are the 3 types of radiation?

Alpha, beta, gamma

What are the characteristics of beta radiation?

2+ charge and relative mass of 4 (2 protons and 2 neutrons). Cannot penetrate skin, travels a few cm in air and can be stopped by paper, cloth

What are the characteristics of beta radiation?

High energy electrons with -1 charge, and almost no mass, penetrate a few mm of skin, travel 1-2 meters in the air and can be stopped by wood, aluminium, steel, bone

What are the characteristics of gamma radiation?

Electromagnetic radiation, pure energy with no mass or charge. They can pass right through the body and travel hundreds of metres in the air. Thick lead or concrete is needed to stop them

State 3 current uses of radioisotopes

Sterilisation of equipment, medical diagnosis/treatment, carbon dating, generation of electricity-nuclear power plants, nuclear weapons.

The number of protons will always be the same as the number of…?

Number of protons in the nucleus

The number of protons will always be the same as the number of…?

Electrons

Mass number - atomic number =

Number of neutrons

Mass number - atomic number =

Number of neutrons

What charge does a neutron have?

+1

What charge does an electron have?

-1

What charge does an electron have?

-1

What is relative atomic mass?

The average of the atomic masses of all the isotopes of that element

What is relative atomic mass?

The length of time it takes for one half of the mass of a substance to undergo radioactive decay