Groups in the periodic table .5

what are group 0 elements known as

noble gases

what are group 0 elements

non-metals

what do group 0 metals exist as

single atoms

what are the boiling points are all noble gases

low boiling points and it increases as you go further down the group meaning the attractive forces between the atoms become stronger

why does the boiling points increase as you go down group 0

This is because, going down group 0:

• the atoms become larger

• the intermolecular forces between the atoms become stronger

• more energy is needed to overcome these forces

chemical property of group 0

they are inert - very unreactive

why are group 0 elements inert

because they are already stable meaning that they have no tendency to lose, gain, or share electrons

what are group 1 elements called

alkali metals

properties if group 1 elements

• are soft (they can be cut with a knife)

• have relatively low melting points

• have low densities

what happens to group 1 elements in a chemical raection

• the one extra electron they have is lost

• they form positive charged ions

alkali metals + water →

metal hydroxide and hydrogen

lithium observation when added to water

Fizzes steadily; slowly becomes smaller until it disappears; forms a alkaline solution

sodium observation when added to water

Fizzes rapidly; melts to form a ball; quickly becomes smaller until it disappears; forms a alkaline solution

potassium observation when added to water

Burns violently with sparks and a lilac flame; quickly melts to form a ball; disappears rapidly, often with a small explosion; forms a alkaline solution

alkaline metals + oxygen →

metal oxides

what happens at room temperature to metals

• oxygen reacts with the surface of the metal

• This forms a white oxide, which covers the surface

• The metal below the surface does not react.

what happens when alkali metals react with oxygen

• burn vigorously when heated and placed in a gas jar of oxygen

• The oxide forms as white smoke

• tarnish (dulls) more quicker as you go down the group

what are the products of alkane metals + chlorine

chlorides

what are chlorides at room temperature

At room temperature the chlorides are white solids. They dissolve in water to form colourless solutions.

lithium reaction with chlorine

• vigorous reaction with red flame

• forms a white crystalline salt

sodium reaction with chlorine

• vigorous reaction with bright yellow flame

• forms a white crystalline salt

potassium reaction with chlorine

• vigorous reaction with lilac flame

• forms a white crystalline salt

trend in the reactivity of group 1 metals

Going down group 1:

• the atoms become larger

• the outer electron becomes further from the nucleus

• the force of attraction between the nucleus and the outer electron decreases

• the outer electron is lost more easily

what are group 7 elements

non-metals

what are group 7 elements called

halogens

what do the halogens exist as

The halogens exist as simple molecules

what is each molecule of the halogens made of

Each molecule is made up of a pair of halogen atoms joined by a single covalent bond.

colour + state of chlorine at room temperature

Pale green + gas

colour + state of bromine at room temperature

brown + liquid

colour + state of iodine at room temperature

purple - black + solid

what happens to the boiling + melting point of group 7 elements are you go down

In group 7, the further down the group an element is, the higher its melting point and boiling point.

why does the melting point and boiling point of group 7 elements increase as you go down

• the molecules become larger

• the intermolecular forces become stronger

• more energy is needed to overcome these forces

what happens to group 7 elements in a chemical reaction

• its atoms each gain one electron

• These atoms form negatively charged ions

halogens + metals →

• salts

• The salts are made up of ions, which are held together by ionic bonds

what happens during the sodium + chlorine reaction

Sodium and chlorine react vigorously when heated, giving an orange flame and clouds of white sodium chloride.

what happens to the reactivity as you go further down group 7

reactivity of the elements decreases down the group

Fluorine + iron wool

Cold iron wool burns to produce white iron(III) fluoride

Chlorine + iron wool

Hot iron wool burns vigorously to produce orange-brown iron(III) chloride

Bromine + iron wool

Hot iron wool burns quickly to produce red-brown iron(III) bromide

Iodine + iron wool

Hot iron wool reacts slowly in iodine vapour to produce grey iron(II) iodide

what happens when a halogen reacts with hydrogen

the product is a compound called a hydrogen halide

what are hydrogen halides at room temperature and what do they dissolve in

• gases

• They dissolve in water to produce acidic solutions

• Hydrogen chloride dissolves in water to produce hydrochloric acid, HCl(aq).

what happens to the reactivity when halogens react with hydrogen

the reactivity of the elements decrease as you go down the group

Fluorine reaction with hydrogen

Explodes at room temperature and in the dark, forming hydrogen fluoride

Chlorine reaction with hydrogen

Explodes with a flame or in sunlight, forming hydrogen chloride

bromine reaction with hydrogen

Vigorous reaction when warmed with hydrogen, forming hydrogen bromide

iodine reaction with hydrogen

Very slow reaction when heated strongly, forming some hydrogen iodide

what is a displacement reaction for halogens

A more reactive halogen can displace a less reactive halogen from solutions of its salts.

trend in reactivity of group 7 elements

• the atoms become larger

• the outer shell becomes further from the nucleus

• the force of attraction between the nucleus and the outer shell decreases

• an outer electron is gained less easily

• the halogen becomes less reactive