1. The Atom

2. Subatomic particles are distinguished by charge and location

3. Nucleus Outside the nucleus Inside the nucleus
Electrons: Cloud of very tiny, negatively charged particles
Mass of electrons is much smaller than that of a proton or neutron
Inside the nucleus
Protons with a positive charge
Neutrons with no charge
Protons and Neutrons are almost identical in size and mass

4. Number of Protons Each element has a unique number of protons
Elements are defined by the number of protons in an atom of that element.
Most atoms don’t have an overall charge
Most atoms have an equal number of protons and electrons. The charges cancel

5. IONS If an atom gains or loses electrons, it becomes charged.
Charged atoms are called Ions
Gain: -
Lose- +

6. ATOMIC NUMBER & ATOMIC MASS
Atomic Number: The number of protons
Atomic Mass: Total number of particles in the nucleus. (Protons & Neutrons)

7. ISOTOPES
Same number of protons but different number of neutrons relative to other atoms of the same element

8. CALCULATING THE NUMBER OF NEUTRONS

9. ACTIVITY Groups of 2 Pick any element on the periodic table
Info needed: Atomic Number, Atomic Mass, number of Protons and number of Neutrons
Make a SHORT story (1-2 paragraphs) about your element. Include all the information above! Be creative!