Why is it often said that mercury will be pervasive when it falls on the ground?

Because mercury is the only metal that exists in a liquid state at room temperature and pressure. Melting point, boiling point, density grams of cubic centimeters. The cohesion is very strong, stable in the air, and mercury vapor evaporates at room temperature, and the vapor is highly toxic.

Natural mercury is a mixture of seven isotopes of mercury. Mercury is slightly soluble in water and increases in solubility in the presence of air. Mercury is ubiquitous in nature, and general animals and plants contain trace amounts of mercury, so there are trace amounts of mercury in our food, which can be metabolized through excretion, hair, etc.

Alloys: Mercury readily alloys with most common metals, and these alloys are collectively referred to as amalgam (or amalgam). Metals that can be alloyed with mercury include gold and silver, but not iron, so iron powder has long been used to replace mercury.

Some other first-row transition metals are difficult to alloy, but do not include manganese, copper, and zinc. Other elements that do not easily alloy with mercury are platinum and some other metals. Sodium amalgam is a commonly used reducing agent in organic synthesis and is also used in high-pressure sodium lamps.

When mercury and the pure metal of aluminium come into contact, they tend to form aluminium amalgam, because aluminium amalgam can destroy the oxide layer that prevents the continued oxidation of aluminium (brush test), so even a small amount of mercury can severely corrode the metallic aluminum. For this reason, in the vast majority of cases, mercury cannot be carried on board because it can easily form a dangerous alloy with exposed aluminum parts on the aircraft.

Liquid: Mercury as a metal is bizarrely liquid at room temperature. The theory of relativistic shrinkage can provide an explanation for this unusual phenomenon.

Similar to gold, the 6S orbital of mercury shrinks and stabilizes at the same time, resulting in an effect known as "inert electron pairs": the 6S2 shell of mercury becomes inert during bonding. It can be seen that the 6s26p excitation energy of mercury far exceeds the corresponding excitation energy of cadmium and zinc.

According to the general periodic law, the energy interval should decrease with the increase of the principal quantum number. Therefore, a smaller energy interval from zinc to cadmium is expected, but the energy interval from cadmium to mercury increases sharply.

Again, it can be seen that it is the relativistic contraction effect that causes the full 6s2 shell to be stable and thus the 6s26p energy interval of mercury increases dramatically. As long as the required excitation energy is not obtained, strong bonds cannot be formed between mercury atoms with an inert 6s2 shell. The ground state Hg2 is only supported by van der Waals forces, so the metallic mercury is liquid at room temperature.

Mercury is dense and is liquid, so it gets in.

Because mercury is heavier and liquid. It is very easy to penetrate.

Mercury is a metallic liquid, so it is pervasive.

Mercury is a liquid metal with a relatively large weight, and liquid objects are easy to penetrate.

Mercury splashing on the ground is more difficult to collect, and it is generally said to be covered with sulfur, the benefit of which is that sulfur and mercury can easily react at room temperature to form mercury sulfide.

Because mercury is the only metal that exists in a liquid state at room temperature and pressure.

Because mercury is a liquid, it has a strong ability to penetrate.

Mercury is a liquid solid with a large mass.

Mercury is a solid in a liquid state, so it is dense.