Question

Magnesium oxide is a binary ionic compound. From its formula, MgO, how do you know that Mg is the metal?

Answer 1

because Oxygen isnt a metal? I'm a bit confused by the question.

Answer 2

because it's listed first, and the convention in writing binary ionic compounds is to list the metal first

Answer 3

thanks. and i wasnt talking about oxygen, i was talking about Magnesium.

Answer 4

so was I

Answer 5

Magnesium falls in grp II, so its a metal. If you look at the periodic table and move across the period; (left-right/GpI-Gp 0), youll notice that the elements are arranged from metals to non-metals
Gp I- Alkali metals
Gp II-Alkaline earth metals...
Also, Mg2+ has the properties of a metal( silver-grey in color, high m.p & b.p, good conductor of heat & electricity,etc...)
Thats why Mg is a metal^^

Answer 6

Also, since ionic bonding is a bonding btwn (metals & non-metals), Mg2+(s) [metal], can react with O2-(g) to give MgO(if u cancel the charges)^^