More and more information Periodic table More and more information

Each Vertical Row is a Period 1 2 3 14

Periods in the Periodic Table Even though they skip some squares in between, all of the rows go left to right. each of the rows is considered to be a different period (PERIODic table). elements have something in common if they are in the same row Common thing is the NUMBER OF ELECTRON SHELLS OR ORBITALS OR ENERGY LEVELS (all different names for same thing)

Practice How many energy levels or e- orbitals does Ca have? How many total e- shells are there? How many e- shells does Ce (#58) have? How many elements are there with only 2 shells?

Groups in Periodic Table

Groups or families in Periodic Table The periodic table also has a special name for its columns. When a column goes from top to bottom, it's called a group or family. The elements in a group have the same number of electrons in their outer orbital. Those outer electrons are also called valence electrons. They are the ones involved in chemical bonds with other elements.

Group Names Every element in the first column (group one) has one electron in its outer shell. Every element in the second column (group two) has two electrons in the outer shell. As you keep counting the columns, you'll know how many electrons are in the outer shell.

Periodic table groups have multiple names Group names can be 1A for the first vertical column that is the red group here. 2A = the orange 3A = the yellow So on until 8A = the purple

And then came complications

Another way to name columns or groups (families) Sometimes the columns are numbered 1 to 18 as in this slide So 1A is also 1 2A is also 2 3A is also 13 4A is also 14 and so forth

Valence Electrons & the Periodic Table Valence electrons are those in the outmost energy level of an atom Atoms in the “A” Groups I through VIII have between 1 and 8 Valence electrons The Group Number gives the number of Valence Electrons for all atoms in that A Group The Period gives the energy level that those valence electrons are in

Numbering the transitional metals The 1-18 counting method takes in the transitional metals (lower) and just counts straight across. Those are called 3B or 13, 4B or 14 , 5B or 15 You don’t have to memorize just recognize

Major sections of Periodic Table

Families Here is an overview / review of the Periodic Table http://www.youtube.com/watch?v=fLSfgNxoVGk

Some fun http://www.youtube.com/watch?v=QA4cFCfoj7c

Families Columns in the periodic table are also called families because they have things in common Just like your family These families have names like your family For example Group I A are the “Alkali Metals” Group VIII are the “Halogens”

IA or 1 is also called the Alkali Metal family Every element in this family has 1 e- in its outermost shell These are the most reactive of all metals Some are common like NaCl or table salt These get more reactive down the group These form bases (alkaline solutions)

Group II A or 2 – Alkaline Earth Metals Family IIA or 2 is also called the Alkaline Earth metals Have 2 electrons in outermost shell Also reactive Magnesium is what makes the white in fireworks and sparklers Calcium is needed for bones and strong teeth Metals get more reactive down the Group

Group VIIA (17) Halogens Every element in this family has 7 e- in its outermost shell These are the most reactive of all nonmetals Most are found in salts like table salt (NaCl) These get more reactive UP the group These form acid solutions They can be gas, liquid or solid

Group VIII A (18) Nobel gases Every element in this family has 8 e- in its outermost shell except Helium (2 electrons) These are all gases These are “inert” meaning unreactive These get denser going down the group Air contains small amounts of these gases