Answer:
The answer is 4
Explanation:
Since magnesium and calcium have the same number of valence electrons, and since the valence electrons are located in the outermost shell so the reasonable is 4

Explanation:
the bottom number would be 54. This is because you add one to 53 to make it 54 and you add 0 to 138.
Nothing at all happens because pure water cannot conduct electricity
acids give away protons (H+), bases accept protons, conjugate bases are what u get when when you take the protons from the acid, and conjugate acids are what u get when you add the protons to the base.
so for (a) the C5H5N is the base, water is the acid, C5H5NH+ is the conj acid, OH- is the conj base
(b) HNO3 is the acid, H2O is the base, hydronium ion is the conj. acid, NO3- is the conj base.