1. Please follow along on the worksheet I gave you. Periodic Table

2. Organization What determines the order the elements are in? Atomic number and the number of protons Why is it such a funny shape? Mendeleev organized elements according to their CHEMICAL traits Each column down has similar chemical properties The column is called a family or group

3. Groups/Families Just like every family, a chemical family has traits in common, but each member is an individual As you go down a family What happens to the mass? It increases What happens to the number of total electrons? The increase What happens to the overall size of the atoms? They increase What happens to the number of VALANCE electrons? They stay the same! The further away from the nucleus the more they will react. Which is more reactive, K or Na? K is further down so it is more reactive

4. Special Groups/Families Group 1- is called the alkali metals All have 1 valence electron. Are they stable? No, they like to get rid of the one e - and form an 1 + ion Group2- is called the alkaline-earth metals All have 2 Valance electrons Are they stable? No, they want to get rid of two e - ’s and form a 2+ ion

5. Group 17- is called the halogen family All have 7 Valence e-’s They want to gain ONE electron to be stable Form -1 ions Are they stable? No they are very reactive and get more reactive as they get larger These are NOT metals Group 18- has two names the Noble Gases or the Inert gases He has 2 valence e-’s. All the rest have 8 valance e-’s. Are they stable? YES! They do not chemically react. Every element is a gas at room temperature. They are NOT metals `

6. What about all the other columns? Each element in a group shares the same number of valance e - ’s. This allows us to predict how each will react. Groups 3- 12 are called the Transition metals As you move across they are going from being the most metallic to least metallic

7. Metals Metals have special PHYSICAL properties Shiny- absorb and reflect light Ductile- made into wire Malleable – can be shaped All are solid at room temperature except Hg Conductors of heat and electricity (means they can move the energy from one place to another.) Most metals have 3-6 valance e - ’s. When the e- from one atom moves, it will cause a neighbor e - to move. They all “jumble together”. The total number of electrons is the same, but they move from atom to atom. We call them “free floating.”

8. Non-metals Not very many of these. They are all on the right hand side of the Table.(Except for H gas.) They like to gain electrons or share electrons. They are brittle and reactive. Groups 17 and 18 are the only two columns that have all non-metals in them

9. Metalloids Elements that are right between the metals and non-metals. The temperature, pressure and other substances around them will determine how they react. There are seven metalloids. The common ones are boron B, arsenic As, and silicon Si Other four are germanium Ge, antimony Sb, and Tellurium Te, Polonium Po

10. Horizontal Organization The rows are called Periods. As you go across the period, the atoms gain ONE proton. Period 1 has only H and He Period 2 has Li, Be, B, C, N, O, F and Ne Each Period starts with an element with 1 valance electron Each Period ends with a NOBLE GAS! A very stable element! Think of the Group 18, being the period at the end of a sentence. We need to start the new sentence and so must go start all over again with one valance e -. As you move across the PERIOD, the atoms get smaller in diameter and start to change and act more and more like a non- metal.