Chapter 16- The Periodic Table

metallic properties

There is a decrease in ________ across a period.

Atomic size

________-- decreases across a period, increases down a group.

Oxygen

________: welding, ________ tents and tanks.

Periodic table

The list of elements arranged in order of increasing proton number.

Group

Vertical column in a periodic table.

Period

Horizontal row in a periodic table.

Same group

- same valency/number of valence electrons

Same period

- same number of shells

Left to right

- gradual change from metals to non-metals

Group I to Group III

- lose electrons to form cations

Group V to Group VII

- gain electrons to form anions

Group IV

- can either gain or lose electrons

Group VIII/O

- are stable and do not react

Atomic size

- decreases across a period, increases down a group

React with cold water to form alkali and hydrogen

2Na + 2H20 2NaOH + H20

React with halogens to form halides

2Na + Cl2 2NaCl

Increases down the group

density, reactivity, softness

Decreases down the group

Melting and boiling points

Undergo displacement reactions

2NaBr + Cl2 2NaCl + Br2

Increases down the group

Melting and boiling points, density, colour (darker)

Decreases down the group

Reactivity, state (gas to solid)

1)       Increases down the group

Boiling point, mass

Helium

for filling balloons and airships

Argon

for filling tungsten bulbs

Neon

used in lights and advertising signs

Xenon

used in vehicle headlamps

Argon

to provide inert atmosphere for processes like welding

Oxygen

welding, oxygen tents and tanks

Transition Metals

The set of metallic elements occupying a central block in the periodic table.

Alkali metals

The name given to Group I metals in the periodic table.

Halogens

The name given to Group VII elements in the periodic table.