Topic: ChemistryAim: How are elements classified in the Periodic Table?

Do Now: An atom has atomic number of 15. How many protons does it have?

Periodic Table of Elements• System of classifying or all of the

known elements and to predict the properties of elements

How are elements arranged?•In order of increasing

atomic number

Element Key

Groups or Families•Columns•Elements have similar BUT NOT

identical properties

Hydrogen• Element does not match the properties of any other

group so it stands alone• Placed above group 1 not part of group 1• Very reactive, colorless, ordorless gas at room temp

•Ex: Family/Group 1: Alkali Metals–soft, white, shiny metals–highly reactive

2:ALKALINE EARTH METALS

Group 2•White and malleable

•Reactive, but less than Alkali metals

3-11:TRANSITION METALS•Range of reactivity & wide range of properties

•Most of the elements on PT

Periods•Rows (7)•Elements not alike in

properties•Left to right atomic #

increases

4 main categories of elements•Metals, Nonmetals, Metalloids,

Noble Gases

1. Metals•88 elements to left of zigzag

line

Physical Properties of Metals• Luster (shininess)

• Ductile (can be pulled into wires)• Malleable (can be hammered into

sheets)• Good conductors (allow heat and

electricity to move through easily)

2. Nonmetals•To right of zigzag line

Physical Properties of Nonmetals

•No luster (dull)•Brittle (break)•Poor conductors of heat and electricity

Sulfur

2. Metalloids•Have properties of both metals and nonmetals

Noble Gases•Last group of nonmetals

•He, Ne, Ar, Kr, Xe, Rn

•INERT gases•Non-reactive

Noble gases glow brightly when electricity is passed through them, and so are used as advertising signs: neon tubes glow red, xenon blue, and krypton bluish-white; argon tubes glow pale red at low pressures, blue at high pressures.

Review:1. Explain how the periodic table of

elements is arranged.2. Elements at the left of the periodic table

are known as3. Elements at the right of the periodic

table are known as4. Explain some of the properties of

metals.5. Explain some of the properties of

nonmetals.6. Explain some properties of noble gases.

3-11:TRANSITION METALS•Good conductors of heat and electricity.

•Some are used for jewelry.

•Can bond with many elements in a variety of shapes.

• 1st element extremely active solid• Last element inactive gas