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.
I think the answer is that is lights up?
Newton's third law of motion states that for every action force, there is an equal and opposite reaction force so that means that the wall is pushing you with the same amount of force that you put on it.
The answer is C, Uranium.
Natural gas, coal, and oil are all naturally made from fossils. Uranium is an element which can be found on the Periodic Table of Elements.
