Question #f444a

1 Answer
May 12, 2017

Answer:

No, they cancel out.

Explanation:

Valency is the combining power of an element.

Let's use #Ca^(2+)# and #O^(2-)#

Valency of #Ca^(2+)#= 2
Valency of #O^(2-)#= 2

When they combine, they cancel out into #CaO#.

(Don't put this on the exam, but you can think of the formula looking like #Ca_2O_2# before they cancel out)

Let's use one more example: #K^+# and #O^(2-)#

Valency of #K^+#= 1
Valency of #O^(2-)#= 2

When they combine, we basically switch the valencies so that the 2 goes by the #K# and the 1 goes by the #O#

So #K_2O_1# but the 1 is understood so we don't write that in the final formula which is #K_2O#