H2 is a covalent bond. Each hydrogen atom shares its single electron to the other, so each hydrogen has two valence electrons (full outer shell).
Answer:
a. 1,2,and 3.
Explanation:
When something turns liquid, e.g. metal, you need to heat it. When something turns gas, e.g. water, you need to heat it. And when something goes directly from solid to gas, e.g. dry ice, carbon dioxide, you need to add heat to it. hope this helps! Please mark brainiest.
Explanation:
So the gas pressure of a helium balloon arises from the impact of the collisions of the helium atoms between themselves and with the inside surface of the balloon. Of course, the outside atmosphere similarly exerts a pressure on the outside of the balloon.
The answer is number 4 or the exchange of energy with the surroundings. Calorimetry is a measurement of energy that is formed or absorbed in a certain process. The calorimeter is the instrument used in order to measure the energy. It is recommended that a calorimeter should be a closed system so as to measure precisely the energy and avoid or lessen the exchange of energy with the surroundings. Thus, comparing an open ceramic mug and an insulated mug with a lid, the greatest difference is the energy lost to the surroundings.
