Chem and Physics GCSE qs for my bro plz help!

hey

my brother has to correct a science paper; I've done the biology for him as I understand that, but depressingly enough I've already forgotten *all* my Physics and Chemistry... (not that I really knew much to begin with)

If you could post the answers to these qs I'd be really grateful and give rep

1) Linda has a piece of red standstone. She hammered it into pieces and then ground them into a powder using a pestle and mortar. She put the powder into a measuring cylinder with water and shook the mixture. The contents settled. Linda said her results showed that sandstone is a mixture of two substances, brown clay and red sand. [diagram]

Linda then poured the cloudy water from the measuring cylinder through filter paper in a filter funnel. She said there might be salts in the colourless, clear liquid that came through the filter.

(i) What could Linda do to find out if there were salts dissolved in the colourless, clear liquid?

(ii) What would she see if there had been salts dissolved in the colourless, clear liquid?

c) Sandstone is a sedimentary rock. Four stages in the formation of sedimentary rock are listed below. They are NOT in the correct order.

compacted deposited weathered transported

Put these stages on the correct order. One has been done for you.

stage 1...weathered...
stage 2...
stage 3...
stage 4...


2) Sophie fills a mug with water and places a coin inside. She pours some concentrated blackcurrant juice into the water. The blackcurrant drink acts like a red filter and makes the coin look red. Explain how a red filter works