The Periodic Table

The Alkaline Earth Metals - Group 2 - Reaction with Oxygen (burning in air).

Magnesium and calcium will both burn in air.
They are sometimes used in the chemicals in fireworks.

Magnesium burns in air with a brilliant white flame to form magnesium oxide.
Magnesium oxide is a base.
magnesium + oxygen  arrow magnesium oxide.
2Mg(s)  +    O2(g)   arrow           2MgO(s)


Calc
ium burns in air with a red flame to form calcium oxide.
calcium + oxygen  arrow calcium oxide (quicklime).
2Ca(s)    +      O2(g)     arrow               2CaO(s)

Calcium oxide is alkaline.
It reacts with water to form calcium hydroxide (slaked lime)
see also the manufacture and uses of lime.

calcium oxide + water  arrow   calcium hydroxide.
CaO(s)     +   H2O(l)    arrow       Ca(OH)2(s)

Although calcium hydroxide is written as solid
it is sparingly soluble in water (it dissolves a little).
The solution is called lime water and is used in the test for carbon dioxide gas.

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