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.
Protons and neutrons are in the center of the atom, making up the nucleus. The charge on the proton and electron are exactly the same size but opposite. Neutrons have no charge.
Answer: The amount of energy needed to move an electron from one zone to another is a fixed, finite amount. The electron with its extra packet of energy becomes excited, and promptly moves out of its lower energy level and takes up a position in a higher energy level.
Explanation:
Answer: Dinitrogen pentoxide
Explanation:
Yes when a firework goes into the sky it releases chemical potential energy which is then changed into kinetic energy
