1. Subatomic Particles

2. Using the Periodic Table N 14.0067 7 Atomic Number Mass Number Symbol

3. Atomic Number - The number of protons in the nucleus  Every element on the Periodic Table has an unique atomic number

4. Determine the number of PROTONS in each: 1. Na 2. O 3. Br 4. Zn 5. H 1. 11 protons 2. 8 protons 3. 35 protons 4. 30 protons 5. 1 proton

5. Mass Number - The number of protons and neutrons (you need to round the decimal number first)  To find the number of neutrons: Mass Number - # of protons From the atomic number

6. Determine the # of protons and neutrons for each of the following: 1. H 2. Cl 3. Mg 4. Ca 5. I 1. 1 proton and 0 neutron 2. 17 protons and 18 neutrons 3. 12 protons and 12 neutrons 4. 20 protons and 20 neutrons 5. 53 protons and 74 neutrons

7. Charge of an atom  Atoms overall charge is always zero (they are neutral)  To achieve this, the positively charged protons must be equal to the negatively charged electrons P + E = 0 for all atoms

8. Determine the number of protons, neutrons, and electrons in each: 1. K 2. Mn 3. P 4. Al 5. H 1. 19p, 19e, 20n 2. 25p, 25e, 30n 3. 15p, 15e, 16n 4. 13p, 13e, 14n 5. 1p, 1e, 0n

9. Ions What atoms turn into when they gain or lose electrons  To find the charge on an ion, compare the # of protons to the # of electrons

10. Example of an Ion Find the number of protons and electrons in a neutral Mg atom: 12 protons and 12 electrons If Mg loses 2 electrons, what will happen to its charge? (+12) + (-10) = +2 Final answer: Mg +2

11. The Complete Chemical Symbol O 16 8 -2 Mass Number (rounded) Atomic Number Charge