Atomic and mass number

Atomic and Mass number

1. Atomic Theory Atoms

2. Atomic number is the number of Protons in an atom All atoms of a particular element have the SAME number of protons (All Carbon atoms have 6 protons) In a neutral atom, T he atomic number =The number of electrons Atomic Number

3. Also called atomic weight or Mass Number Sum weight of protons and neutrons in an atom Mass Number

4. Calculate the mass number of each of the following atoms

5. O 8 16 Atomic number Mass number Symbol Oxygen Name Atomic number= Number of protons= Number of electrons Mass number= Number of protons + Number of neutrons

6. Calculating Neutrons: Mass number = protons + neutrons so….. Neutrons = mass number – protons What is the number of neutrons of the following atom ? A 21 45