Very clean water

Highly polluted water

Water has high amount of fluoride compounds

Slightly polluted water

b

d

c

a

K

Be

Ca

Mg

$4 \mathrm{LiNO}_{3} \stackrel{\Delta}{\longrightarrow} 2 \mathrm{Li}_{2} \mathrm{O}+4 \mathrm{NO}_{2}+\mathrm{O}_{2}$

$2 \mathrm{LiNO}_{3} \longrightarrow 2 \mathrm{Li}+2 \mathrm{NO}_{2}+\mathrm{O}_{2}$

$4 \mathrm{LiNO}_{3} \stackrel{\Delta}{\longrightarrow} 2 \mathrm{Li}_{2} \mathrm{O}+2 \mathrm{~N}_{2} \mathrm{O}_{4}+\mathrm{O}_{2}$

$2 \mathrm{LiNO}_{3} \stackrel{\Delta}{\longrightarrow} 2 \mathrm{NaNO}_{2}+\mathrm{O}_{2}$