Question

the chemical name of HNO2 is
1- nitric acid
2- nitrous acid
3- hydrogen nitrite
4- none of the above
the valency of oxygen is
1-2
2-4
3-6
4-8
atomic numbers is equal to
1- number of electrons
2- number of protons
3- number of protons plus number of neutrons
4- number of protons plus number of electrons
5- others
which of the following do not have +3 valency
1-ferric
2-phosphide
3-alluminium
4-arsenic

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Answer 1

2 - Nitrous acid

1 - 2

2 - number of protons

2 - phosphide