Why does chlorine react vigorously with hydrogen in the presence of sunlight?

chlorine has a great attraction for hydrogen’s electron.
chlorine has a great attraction for hydrogen’s nucleus.
chlorine has a great attraction for hydrogen’s proton.
chlorine want to donate an electron to hydrogen.

Chlorine react vigorously with hydrogen in the present of sunlight because chlorine has a great attraction for hydrogen's electron. During the reaction, chlorine  and hydrogen will donate one electron each from their valence electrons which will be shared equally by both elements, thus forming a covalent bond.

Answer//the law of conservation of mass.;

Answer

it is the minimum amount of material needed to sustain a fission reaction.

explanation

critical mass is the minimum amount of fissionable material that must be assembled for a sustained fission reaction to take place. although two to three neutrons are produced for every fission, not all of these neutrons are available for continuing the fission reaction. if the conditions are such that the neutrons are lost at a faster rate than they are formed by fission, the chain reaction will not be self-sustaining.   at the point where the chain reaction can become self-sustaining, this is referred to as critical mass.