-7 = 3s - 1
+1 +1 (add 1 to both sides to get the variable alone)
___ ____
-6 = 3s
__ ___ (-6 and 3s both divided by 3)
3 3
-2 = s
Yep!
the abbreviated electron configuration of sodium is (Ne) 3s1
3s1
1s22s22p63s1 or [Ne]3s1
[Ar] 3s1
1s2, 2s2, 2p6, 3s1. It the the '3s1' electron that readily ionises m because it is in the outer most electron energy shell.
To find the number that, when multiplied by 7, equals 49, you can divide 49 by 7. Doing the calculation, 49 divided by 7 equals 7. Therefore, 7 times 7 equals 49.
1s2 2s2 2p6 3s1
[Ne]3s1
16-7 equals = 9
37-7 equals = 30
x = 14