1	M4 Periodic Table II: Patterns & Trends
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: Physical properties, chemical properties, metal, non-metal, Melting point, boiling point, density unreactive, ductile, malleable, sonorous, conductor, insulator, state, solid, liquid, gas Electronic configuration, electronic structure, shell, outer (valence) shell, valence electrons,
3	Learning Objectives Skills: Describe the change from metallic to non-metallic character across a period Describe the general physical properties of metals and non-metals 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 Describe the general trend and pattern in structure of atoms across period and down group Describe in general the trend and pattern in physical state across period and down groups
4	Classification An element according to its physical properties, is classified as being a Metal, metalloid or a non-metal
5	Physical properties Metal Metalloid Non-metal Dense Malleable Brittle Ductile Conduct electricity poor conductor do not conduct electricity (except graphite (carbon) Conduct heat poor conductor poor heat conductors (insulators) Shiny (when freshly cut) Most have high high melting pt. melting point Most have high high boiling pt. boiling point SONOROUS (ring when struck)
6	The physical states Most of the metals and all metalloids are in the SOLID state of matter at room temperature. Non-metals can be solid, liquid or gas.
7	Trends and patterns in Physical State Across the period, the trend is for it to go from solid to gas. Down the group, if there is a trend, then the trend is from gas to liquid to solid or gas to solid.
8	Trends and patterns in the Periodic table
9	Group The number of electrons in the outer-most shell is referred to as the valence electrons. In the periodic table, the number of valence electrons in the atom of an element determines the group it belongs to.
10	Period Similarly, the period an element belongs to represents the number of shells the atom of the element contains.
11	Practice Questions 1) How many electrons in the outer shell of Magnesium (in group 2)? 2) Lithium is in period 2 – how many shells does it have in total ? 3) Potassium is in period 3 – how many shells does it have in total ? 4) What is the relationship between period and number of shells ?
12	Practice Questions 5) Describe the trend in the size of atoms going down a group. Explain. 6) Describe the trend in the size of atoms going across a period. Explain.