ATOMS
All matter is made up of atoms and there
are over 100 different types of atoms.
An element is a substance that only
contains one type of atom.
Atoms can combine together to form
compounds.
Atoms are made of three particles: protons,
neutrons and electrons.
1- Protons have mass and a positive
charge.
2- Neutrons have mass and no charge.
3- Electrons have no mass and a negative charge.
Protons and neutrons are in the nucleus
and electrons are in the shell orbiting the nucleus.
The atomic number (Z) is the number of
protons in an atom and the mass number (A) is the number of protons plus the
number of neutrons
