Hydrogen gas reacts explosively with fluorine, even at low temperatures, to form hydrogen fluoride, HF. Predict and explain how astatine might react with hydrogen. Include a balanced equation in your answer.

< > according to newton's third law of motion, forces always act in equal but opposite pairs. another way of saying this is for every action, there is an equal but opposite reaction.< >

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter  

there are two significant figures.

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.