Edexcel (9-1) Topic 6

Which of the following elements is a halogen?

Select all elements that are group 1 metals

Group 1 of the periodic table are commonly known as [blank_start]Alkali Metals[blank_end]. They are found in the first column of the periodic table because they only have [blank_start]one[blank_end] electron on their outer-shell. They are soft, and have generally [blank_start]low[blank_end] melting points (for metals).

chlorine + hydrogen → [blank_start]hydrogen chloride[blank_end] bromine + sodium → [blank_start]sodium bromide[blank_end] potassium + water → [blank_start]potassium hydroxide[blank_end] + hydrogen

[blank_start]Alkali metals[blank_end] become more reactive, the larger the atom. This means the [blank_start]metals[blank_end] near the top of the group (lithium, sodium etc) are much [blank_start]less[blank_end] reactive than those near the bottom of the group (rubidium, caesium etc). This is because the outer negative electron is [blank_start]further away[blank_end] from the positive nucleus, meaning it [blank_start]doesn't feel as much[blank_end] attractive force and so can be more easily lost.

At room temperature: Chlorine is a pale green [blank_start]gas[blank_end] Bromine is a [blank_start]brown[blank_end] liquid Iodine is a purple-black [blank_start]solid[blank_end]