One because Potassium is in the first column on the periodic table. Any element in the first column on the periodic table has one valence electron in their outer shell.
Answer:Is this from the stochiometry unit?
Explanation:
AN element is composed from atoms with the same number of protons,
A compound contain two or more different elements
Answer: Option (D) is the correct answer.
Explanation:
Atomic number of chlorine is 17 and its electronic distribution is 2, 8, 7.
So, in order to attain stability it tends to gain one electron from a donor atom. Therefore, a chlorine ion is formed as
.
As it gains only one electron that is why, -1 charge occurs.
Whereas Ar is a noble gas with atomic number 18. As it has completely filled octet so it will be unreactive in nature as it is already stable.
Similarly, He is also a noble gas so it is unreactive in nature.
Atomic number of boron (B) is 5 with electronic distribution 2, 3. So, in order to attain stability it needs to lose 3 electrons.
Thus, we can conclude that Cl is the atom which tends to gain 1 valence electron from another atom in order to become stable.