Fill in the missing word. Nuclear fusion is difficult to achieve because at low temperatures and pressures the positively charged nuclei of deuterium and tritium electrostatically
each other.

Nuclear fusion is difficult to achieve because at low temperatures and pressures  the positively charged nuclei of deuterium and tritium electrostatically  each other is explained below in complete details.

Explanation:

For nuclear fusion to happen, very eminent temperatures are needed to succeed the opposing force between the positively energized nuclei of a specific isotope.  Fusion doesn't release dangerous toxins like co2 or other greenhouse gases into the environment. Its significant by-product is helium: an inactive, non-toxic gas. No long-lasting radioactive ruin: Nuclear fusion reactors generate no high action, long-lived nuclear ruin.

float.

archimedes' principle

denser than water sinks in water.

denser than mercury would sink in it