A soft silvery metal with a melting point of 63.5`C reacts with chlorine gas. The substance formed by the reaction is a white crystalline solid with a density of 1.98 g/cm3. Is the new substance sodium chloride? Explain.

No.

Sodium Chloride has a density of 2.17 g/cm3

Explanation:

-The resultant crystal is likely to be of Potassium Chloride

-The silvery metal is likely Potassium due to it's similar melting point of 63.5 °C which when reacts with Chlorine gas form a Potassium chloride with the following properties:

Hence, the crystal formed is not Sodium Chloride.

-The properties of sodium chloride are:

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

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.