2. ATOMS Atoms are the building blocks of all matter. An atom is made up of smaller bits called… NameChargePositionMass Protons Electrons Neutrons +ve -ve neutralNucleus Outside Nucleus1 0 1

3. ELEMENTS An element is a substance made up of only 1 type of atom. There are about 112 different atom types therefore there are 112 elements. These are shown on the periodic table of the elements. On the periodic table each atom type has its information. For example… Atomic no. Symbol Name Atomic mass.

4. PERIODIC TABLE Any atom can be identified by the atomic no., the symbol or by the name. For instance... Atomic no. Symbol Name SymbolAtomic No. Hydrogen Fe 12 Iron Magnesium H Mg 1 26 The information from the table can also be shown as: 11 5 B

5. WHAT IT MEANS The Atomic Number: = number of protons = number of electrons (as an atom has the same of each) The Mass Number: = number of protons + neutrons - why are electrons not included in the mass no? They have no mass! So for Boron… Protons = Electrons = Neutrons = 5 5 6 What about Phosphorus? Protons = Electrons = Neutrons = 15 16 11 5 B

6. Select the correct symbol for each: A. Calcium 1) C2) Ca3) CA B. Sulfur 1) S2) Sl3) Su C. Iron 1) Ir2) FE3) Fe

7. Select the correct name for each: A. N 1)neon 2)nitrogen 3)nickel B. P 1)potassium 2)phlogiston3)phosphorus C. Ag 1) silver 2)agean3)gold

8. ELECTRON ARRANGEMENT Electrons are very fast moving. They are arranged in shells around the nucleus using the rule 2,8,8. The first shell fits up to… The second fits up to… The third fits up to… So the electron shell arrangement for 12 Mg would be… 2 e 8 e 2, 8, 2

9. GROUPS The columns in the periodic table are called groups. Groups of elements share similar reactivity. This is because they have the same number of valence electrons. As you go down a group the reactivity increases. Group 1 are the alkali metalsalkali metals properties: good conductors solid at room temperatures can be cut with a knife low densities and melting points Group 17 are the Halogens

10. * The rows in the periodic table are called periods. * Atom’s size decreases from left to right in a given period * The period tells you the number of energy shells in an atom.

11. A. Element in Group XVII, Period 4 1) Br2) Cl3) Mn B. Element in Group II, Period 3 1) beryllium2) magnesium 3) boron