8 2 group properties and trends

Group I is called the alkali metals.

The two products formed when sodium reacts with water are sodium hydroxide and hydrogen.

Properties of Group 1 metals are:

The alkali metals share similar chemical properties because they all have one electron in their outer shell.

lithium + water lithium hydroxide + hydrogen

The balanced symbol equation for the reaction between potassium and water is: 2K (s) + 2H2O (l) ⟶ 2KOH (aq) + H2 (g)

The product formed when sodium reacts with oxygen is sodium oxide.

Going down Group 1, reactivity increases.

The electronic configuration of potassium is 2.8.8.1.

Going down Group 1, melting point decreases.

True. Going down Group 1, density of the elements increases.

Group VII of the Periodic Table is the called the halogens.

Fluorine is in Group 7 of the Periodic Table because it has 7 electrons in its outer shell.

The colour and state of chlorine at room temperature is a pale yellow-green gas.

Going down the group, the density of the halogens increases.

The colour and state of bromine at room temperature is a red-brown liquid.

The formula of a chlorine molecule is Cl2.

The colour and state of iodine at room temperature is a grey-black solid.

False. The halogens are diatomic.

Going down Group VII, reactivity decreases.

A halogen displacement reaction is one where a more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide.

The word equation for the displacement reaction between potassium bromide and chlorine is: potassium bromide + chlorine → potassium chloride + bromine

The balanced symbol equation for the reaction between potassium iodide and bromine is: Br2 + 2KI → 2KBr + I2

Iodine cannot displace chlorine from potassium chloride because iodine is less reactive than chlorine.

The solution will turn orange.

The charge of the ions formed when halogens react with Group 1 metals is 1-.

True. When potassium iodide reacts with bromine, a brown solution is formed.

Transition elements are located in the middle of the Periodic Table, between Group 2 and Group 3.

Typical properties of transition elements include:

True. Transition metals have ions with variable oxidation numbers.

The oxidation number of Fe3+ is +3.

False. Transition elements have high densities.

False. Transition metals do have the properties typical of a metal.

True. Transition elements are useful as catalysts.

Transition elements have more than one oxidation number because they can lose different numbers of electrons.

Fe has lost 2 electrons to become Fe2+.

True. Compounds containing transition elements in different oxidation states will have different properties and colours.

Group VIII of the Periodic Table is the noble gases.

Noble gases are unreactive as they have full outer shells of electrons.

False. The Group 0 elements are all non-metal, monatomic, colourless, non-flammable gases at room temperature.

The electronic configuration of neon is 2.8.

True. Noble gases are inert (unreactive).