16. The valency of sodium is +1 and that of chlorine is -1, why?​

Explanation:

Since sodium has only one electron in the outermost shell which takes part in the bonding its valency is +1 . Chlorine atoms can accept the electron in 3p orbital to attain the nearest noble gas configuration of Ar . Chlorine has 7 valence electrons. It requires one more electron to complete its octet.

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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