What's the problem ? Hardness is not the definition of a metal.
You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.
The answer is B, you just check if it is the same on the left and right side
A:
Left side - Right side
2xH - 2xH
1xS - 3xS
4xO - 12xO
2xAl - 2xAl
Therefore A is not correct
B:
Left side - right side
2xK - 2xK
1xCl - 1xCl
1xPb - 1xPb
2xN - 2xN
6xO - 6xO
B is therefore correct as both sides add up
Wouldn't be a then not c if both were solutions.
Aspartame produces 4 kilocalories of energy per gram when metabolized, While table sugar produces 3.9 kilocalories. However, aspartame is approximately 200 times sweeter than table of sugar, so it is consumed in much smaller doses. Then we can say that they're pretty much the same
