C1 - Principles of Chemistry
Atom = 3 subatomic particles
- protons (found in nucleus with mass 1)
- neutrons (found in nucleus with mass 1)
- electrons (orbiting the nucleus with mass 1/1840)
Elements are made up of only one type of atom
The atomic number of the element in the periodic table tells us the number of protons and electrons - this is the smaller number.
The number of neutrons = nucleon number - the atomic number
Gold (Au) - Nucleon number is 197 and atomic number is 79
- 197 - 79 = number of nucleons = 118
- Number of protons and electrons is 79.