chemistry - group 1 and group 7 properties

lithium flame colour

red

sodium flame colour

orange

potassium flame colour

lilac

in what way do all the metals in group 1 react with water?

they all react vigorously to create an alkaline solution and a gas

gas given off when group 1 metals react with water

hydrogen

which metal out of Li, Na, K reacts the most violently with water?

potassium

how does lithium react with water?

fizzes steadily

how does sodium react with water?

it melts into a ball and then fizzes quickly

how does potassium react with water?

gives off sparks and hydrogen; burns with a lilac flame

how can you tell potassium is the most reactive?

it reacts the most vigorously with water and produces the most bubbles

what is the trend in reactivity of metals in group 1?

more reactive as you go down the group

why do the group 1 elements have similar properties?

they all have one electron in their outer shell

give physical properties of group 1 metals

soft, low melting points, very reactive

colour and state of chlorine at rtp

yellow-green gas

colour and state of bromine at rtp

red-brown liquid

colour and state of iodine at rtp

purple solid

what is the trend in physical properties of group 7 elements?

as you go down the group the melting/boiling points get higher - go from gas to liquid to solid at rtp

knowing the physical properties trend, how can you predict properties of other halogens?

higher than chlorine - gas at rtp

lower than iodine - solid at rtp

in a displacement reaction with KBr, KI, which halogens will chlorine displace?

chlorine will displace bromine and iodine

in a displacement reaction with KCl, KI, which halogens will bromine displace?

bromine will displace iodine but not chlorine

in a displacement reaction with KCl, KBr, which halogens will iodine displace?

iodine will not displace chlorine or bromine

what is the trend in reactivity of the halogens?

as you go down the group, the reactivity decreases