1	M4 Periodic Table I: Periodic Table
2	Learning Objectives Pre-requisite: Be able to recall the symbol, position (atomic number), electronic structure and electronic configuration for the first 20 elements in the periodic table. Concepts: Symbol, formula, Element, group, period, atomic number, relative atomic mass Alkali metal, alkaline earth metal, halogen, transition metal Electronic configuration, electronic structure, shell, outer (valence) shell, valence electrons,
3	Learning Objectives Skills: Be able to describe the difference between a symbol and a formula for an element Be able to identify the diatomic molecular elements in the periodic table Be able to identify the elements that exist in the liquid and gaseous state Describe the relationship between group number, number of valence electrons and metallic/non-metallic character Describe the relationship between period number and number of shells in the atom of an element
4	Why is the Periodic Table important? The periodic table is the most useful tool to a chemist. It organizes an incredible amount of information about all the known elements…in just a small table.
5	Pre-Periodic Table Chemistry … …was a mess!!! As therefore no organization of elements, information was difficult to come by. Chemistry didn’t make sense. It was like going shopping to a store that had no organization to speak of.
6	Dmitri Mendeleev: Father of the Table HOW HIS WORKED… Put elements in rows by increasing atomic weight. Put elements in columns by the way they reacted. SOME PROBLEMS… He left blank spaces for what he said were undiscovered elements. (Turned out he was right!) He broke the pattern of increasing atomic weight to keep similar reacting elements together. Some different elements have the same mass e.g. Cobalt and Nickel Polonium & Astatine
7	The Current Periodic Table Mendeleev wasn’t too far off. Now the elements are put in rows by increasing ATOMIC NUMBER!! The elements are listed in the periodic table from: left to right across in increasing atomic (proton) number. There are approximately 115 elements Everything in the Universe is made of 1 or more elements. The horizontal rows are called periods and are labeled from 1 to 7. The vertical columns are called groups are labeled from 1 to 8.
8	Periodic table
9	Groups…Here’s Where the Periodic Table Gets Useful!! Elements in the same group have similar chemical and physical properties!! (Mendeleev did that on purpose.) Not only that, there is a pattern to their properties.
10	Families on the Periodic Table Columns are also grouped into families. Families may be one column, or several columns put together. Families have names rather than numbers. (Just like your family has a common last name.)
11	The Periodic Table
12	The Periodic Table
13	The Periodic Table
14	The Periodic Table
15	Hydrogen Hydrogen belongs to a family of its own. Hydrogen is a diatomic, reactive gas. Hydrogen was involved in the explosion of the Hindenberg. Hydrogen is promising as an alternative fuel source for automobiles. It is used as rocket fuel.
16	Alkali Metals 1^st column on the periodic table (Group 1) not including hydrogen. Very reactive metals, always combined with something else in nature (like in salt). Soft enough to cut with a butter knife.
17	Alkaline Earth Metals Second column on the periodic table. (Group 2) Reactive metals that are always combined with nonmetals in nature. Several of these elements are important mineral nutrients (such as Mg and Ca).
18	Transition Metals Elements in the middles of the periodic table. Less reactive, harder metals. Includes metals used in jewelry and construction. Metals used “as metal.”
19	Boron Family Elements in group 3 Aluminum metal was once rare and expensive, not a “disposable metal.”
20	Carbon Family Elements in group 4 Contains elements important to life and computers. Carbon is the basis for an entire branch of chemistry. Silicon and Germanium are important semiconductors.
21	Nitrogen Family Elements in group 5 Nitrogen makes up over ¾ of the atmosphere. Nitrogen and phosphorus are both important in living things. Most of the world’s nitrogen is not available to living things. The red stuff on the tip of matches is phosphorus.
22	Oxygen Family Elements in group 6. Oxygen is necessary for respiration. Many things that stink, contain sulfur (rotten eggs, garlic, skunks, etc.) .
23	Halogens Elements in group 7. Very reactive, volatile, diatomic, nonmetals Always found combined with other element in nature . Used as disinfectants and to strengthen teeth.
24	The Noble Gases
25	The Noble Gases Elements in group 8 (group 0). VERY unreactive, monatomic gases Used in lighted “neon” signs Have a full valence shell.
26	Elemental symbol and formula The entry for every element contains a symbol and two numbers. Symbol: One- or two-letter representation for an element. For instance, the symbol for element hydrogen is the letter “H.” Oxygen, O, and sodium, Na, not S. S is the symbol for Sulfur. Symbol for nitrogen is N, but for potassium it’s K, not P. P is the symbol for Phosphorus. The two numbers are atomic number and relative atomic mass. Atomic number represents the number of protons in the nucleus. Relative atomic mass representative how heavy the atom is relative to the mass of hydrogen atom.
27	Elemental symbol and formula Formula: one or two letter symbol with a numerical subscript (1 being understood) that represents a single unit of the fundamental particle (one atom or one molecule or a formula unit) that makes up the substance. Two variety of elements: Monatomic: The formula is the same as the symbol, eg. He, Ar, Na. The formula shows that the elementary particles are atomic. Diatomic: Formula contains the subscript 2, eg. H₂, O₂, N₂. Elementary particles are molecules—diatomic molecules. Molecules are particles that are made up of two or more atoms combined (bonded) together. Only the following elements in the periodic table are diatomic elements: Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Bromine and Iodine. The rest are monatomic.
28	Diatomic Elements
29	Formula and Chemical symbol for some compounds
30	Classification An element according to its physical properties, is classified as being a Metal, metalloid or a non-metal
31	Practice Questions 1. J04/2/5. Look at the list of five elements below. argon bromine chlorine iodine potassium (a) Put these five elements in order of increasing proton number. [1] (b) Put these five elements in order of increasing relative atomic mass. [1] (d) Which of the five elements in the list are in the same group of the Periodic Table? [1] (e) (i) From the list, choose one element which has one electron in its outer shell. [1] (ii) From the list, choose one element which has a full outer shell of electrons. [1]
32	Practice Questions 2. J00/2/1. The diagram shows part of the Periodic Table.
33	Practice Questions (ii) Write down the symbol for an element with a smaller proton (atomic) number than lithium, Li. (iv) Write down the symbol for an element which contains atoms with a full outer shell of electrons. [3]
34	Practice Questions 3. (b) The diagram shows the atomic structure of an atom of lithium.
35	Practice Questions (c) The diagrams show the electronic arrangement of the atoms of two elements.
36	Practice Questions (ii) Why are these two elements in the same group of the Periodic Table? [1] 4. The diagram shows an outline of the periodic table.
37	Practice Questions Choose your answers only from the letters shown on this outline table. Which letter, A to H, represents an element which: (a) is in Group 3, Letter ............................ [1] (b) is in Period 2, Letter ............................ [1]