Barium forms cation : Ba²⁺
<h3>Further explanation</h3>
Given
Barium element
Required
Ion type
Solution
Barium with the symbol Ba is an alkaline earth metal element having the atomic number 56
Electron configuration of Barium: [Xe] 6s2
If we look at this configuration, then Barium will try to achieve stability by removing 2 electrons so that the electron configuration is the same as the noble gas Xenon (Xe)
Because it removes 2 electrons, Barium has the number of protons> the number of electrons so that the charge is positive and forms a cation
The answer would be A: its container.
Gas will expand to fill whatever container it is put in.
The noble gases AKA the column with full outermost valence shells. (Group 18)
They do form directly on the equators
