1. different gases mix together to form air and no new comound is formed
2. air has variable composition
3. air shows the properties of its constituent substances
Radio waves
microwaves
infrared waves
red waves
orange
yellow
green
blue
violet
Ultraviolet
xrays
gamma
<span>Net Ionic equation: 3Zn^2+(aq) + 2PO4^3-(aq) ---> Zn3(PO4)2 (s)
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Explanation:
(a) potassium oxide with water

According to reaction,1 mole of potassium oxide reacts with 1 mole of water to give 1 mole of potassium hydroxide.
(b) diphosphorus trioxide with water

According to reaction,1 mole of diphosphorus trioxide reacts with 2 moles of water to give 2 moles of phosphorus acid.
(c) chromium(III) oxide with dilute hydrochloric acid,

According to reaction,1 mole of chromium(III) oxide reacts with 6 moles of hydrochloric acid to give 2 moles of chromium(III) chloride and 3 moles of water.
(d) selenium dioxide with aqueous potassium hydroxide

According to reaction,1 mole of selenium dioxide reacts with 2 moles of potassium hydroxide to give 1 mole of potassium selenite and 1 mole of water.