Answer:
The answer to your question is the third option, atoms of each lose one electron to achieve stability.
Explanation:
a) The first option is incorrect, those elements are extremely reactive and can explode.
b) The option is also incorrect, metalloids are located in groups 3A, 4A OR 5A in the periodic table.
c) This option is correct
d) These elements have 1 valence electron, this option is wrong.
The spontaneous decay of an atom is called transmutation
From the periodic table, beryllium has an atomic number 4. This means that beryllium has 4 electrons.
Now, the first energy level can hold only 2 electrons (which will occupy the s sublevel) wile the remaining two electrons will occupy the second energy level (also in the s sublevel).
Based on the above, the electronic configuration of beryllium will be as follows:
1s2 2s2
