The correct answer is D
According to the law of conservation of mass, mass can not be destroyed or lost, it can just be rearranged in space, turned into energy etc.
Therefore, in our of example the wood was burned and turned into ashes. Even though the ashes weight less than the original wood, some of the solid mass of the wood was converted to gas and energy, so the overall mass remained the same.
On the left side. The alkali metals are group 1, the alkaline earth metals are group 2, and the transition metals are groups 3-12.
