Which of the following is of particular interest to scientists in their observations because of potential threats to the earth? meteors dust comets near earth objects (neos)

The answer is Near Earth Objects (NEOs).

Near Earth Objects (NEOs) have gained particular interest to scientists in their observations because of its potential threats to the Earth. It can be comets or asteroids. It is called Near Earth since their orbits are too close to cross the orbit of the Earth thus NEO can reach the space near-Earth that more likely give potential threats to the Earth.

float.

archimedes' principle

denser than water sinks in water.

denser than mercury would sink in it