Which heat-treating operation would be performed when the surface of the metal is changed chemically by introducing a high carbide or nitride content?

Case-hardening

Explanation:

Case-hardening

It is the process of hardening the surface of the metal object and allowing the metal which is deep inside to remain soft , hence , making a thin hard outer layer on the surface .

In case of iron which have low carbon content , the case - hardening is done by introducing high carbide or nitride content .

The process of case - hardening is done , in the final shaping process .

given below.

Explanation:

1) True

In nuclear fusion atomic nuclei splits and in nuclear fission atomic nuclei combines.

2) correct answer is option A

self sustaining reaction product causes new reactions.

3) correct answer is option A

in nuclear fission the combined atomic mass of daughter nuclei is more than the parent nuclei.

4) correct answer is option B.

high temperature is the must requirement for fusion to take place because it gives hydrogen atoms enough energy to overcome the electrical repulsion between the protons.

5) True

uranium-235 is used in nuclear reactors where as plutonium-239 is used in making of nuclear weapons.