Elements

What is an element?

• An element is a pure substance that is not combined with any other substance nor can be broken down any farther

Periodic table

• Elements are arranged on the periodic table by varying factors such as atomic structure (how the subatomic particles such as protons, neutrons and electrons are arranged), reactivity, melting point and ionization energy

Periodic Table

• Columns up and down the table are called families or groups.

• Rows across the table are called periods.

Atomic size

• As you go DOWN a family size INCREASES

• As you go ACROSS a period size DECREASES

• So…biggest atoms are in the bottom left corner of the table

Reactivity

• Reactivity is how likely and violently the atom will react with other substances

• Metals- reactivity decreases across a period and increases down a family

• Non-metals- reactivity increases across a period and decreases down a family

Melting point

• Metals- decreases as you go down a family

• Non-metals- increases as you go down a family

Ionization energy

• Ionization energy is the amount of energy required to remove the outermost electron

• Increases as you move across a period and decreases as you go down a group