Mercury Charge: Properties & Reactions Of The 0, +1, And +2 Charge

All atoms in their neutral states do not have any charge. When they dissociate in a solute or are in reactions with other molecules, they tend to form ions and carry a charge. Metals like mercury tend to exhibit more than one charge.

Despite the multiple charges, mercury is not a transition metal because the d-subshells in its electronic configuration are filled up. The charge mercury exhibits depends on how it reacts with other elements. It forms compounds with elements such as oxygen, chlorine, sulfur, etc.

Let’s look at the charge mercury exhibits when in compounds with different elements.

Properties of mercury

  • Mercury is a block d element located in group 12 and period 6.
  • It is a silvery metal that is a liquid at room temperature with a density of 13.5 g/cm3.
  • It has atomic number 90 and mass number 200.59.
  • Also, mercury has an electronic configuration of (Xe)4f145d106s2 with 2, 8, 18, 32, 18, and 2 electrons in its shells.
  • Mercury commonly occurs in its +1 and +2 oxidation states. But in a few cases, it may exhibit a +4 state.

What is the charge of mercury?

Mercury exhibits various charges because it can also exhibit multiple oxidation states. Mercury can have 0, +1, or +2 charges. Each charge has different properties in terms of conductivity, solubility, toxicity, melting point, and boiling point.

The charge of mercury also determines its application and how it reacts with other elements.

The 0 charge

Mercury (0) is quite common, but it bears no charge. This is elemental mercury, also known as metallic mercury or quicksilver. This is mercury which is a liquid metal at room temperature and pressure.

Mercury (0) forms an amalgam with metals such as tin, silver, and gold. Upon heating, this liquid mercury forms a colorless, odorless, but toxic gas. Unlike other forms of mercury, this mercury is insoluble in water but soluble in organic solvents.

In addition, this mercury has a melting point of -37.89°F (-38.83°C) and a boiling point of 674.11°F (356.73°C). Mercury (0) is also a good electricity conductor.

The +1 charge

This is mercurous mercury or monovalent mercury. It has a +1 charge and is the least stable of the three forms of mercury. It is very rare but does exist.

Mercury (I) exists in colorless and white solids. It usually exists as a dimer in the form of Hg22+. When it reacts with chlorine, it forms mercurous chloride (Hg2Cl2), which will decompose into mercury (II) chloride upon heating.

Furthermore, it has melting and boiling points of 530°F (277°C) and 721°F (383°C), respectively. When it forms mercury (I) chloride, it is slightly soluble in water and insoluble in organic solvents. Also, mercury (I) is a poor conductor of electricity and a poor insulator as well.

The +2 charge

Mercury with the +2 charge, Hg2+, is the most common charge for this metal. It is called mercuric mercury or divalent mercury. It is very stable and reacts well with elements such as sulfur, oxygen, chlorine, and nitrogen.

Additionally, Hg2+ has a melting point of 528°F (326°C) and a boiling point of 579°F (304°C). It usually forms colored compounds.

When present as mercury (II) chloride, it is highly soluble in water but insoluble in organic solvents. Also, it is a poor conductor of electricity and a poor insulator as well.

Examples of mercury compounds with the +2 charge are mercury sulfide (HgS), mercuric chloride (HgCl2), and methylmercury (CH3Hg+).

What reactions does mercury undergo?

The reactions mercury undergoes vary with the different forms and certain other factors.

With oxygen

For instance, when mercury reacts with oxygen under high temperatures such as 662°F (350°C), it forms mercury (II) oxide, HgO. If the temperature rises 50°F higher, HgO will decompose into the constituent elements.

2Hg + O2 → 2HgO (at 662°F)

With halogens

When mercury reacts with any halogen, it forms mercury (II) salts of that halogen. For instance, it reacts with chlorine to yield mercuric chloride (HgCl2).

But, on further reaction with elemental mercury, HgCl2 will become Hg2Cl2. This is the same for all halogens.

Hg + Cl2 → HgCl2

HgCl2 + Hg → Hg2Cl2

With other metals

Mercury dissolves heavy metals such as gold, sodium, silver, and tin to form alloys called amalgams. These amalgams have great importance.

Sodium amalgam is an excellent reducing agent, and the amalgam it forms with gold is used in the process of gold purification and gold plating.

With acids

Mercury is not a very reactive metal. It does not react with all acids as other metals do; it reacts only with oxidizing acids. Examples of these acids are concentrated sulphuric acid and concentrated nitric acid.

When mercury reacts with any of these acids, it yields mercury (II) salts with contain oxides of sulfur or nitrogen, depending on the acid.

Hg + 2H2SO4 → HgSO4 + SO2 + 2H2O

Hg + 2HNO3 → Hg(NO3)2 + H2

Mercury reacts with dilute nitric acid but not dilute sulphuric acid.

2Hg + 2HNO3 → Hg2(NO3)2 + H2


What is the nuclear charge of mercury?

The nuclear charge of mercury is 90. Its nucleus contains 90 protons which are responsible for the charge on the nucleus.

Can mercury form anions?

Mercury does not readily form anions. It is a metal that forms a divalent cation because it loses two electrons in its valence shell and gains a positive charge as it forms an ion.

If mercury has any tendency to form anions, it will rarely do so.

Why is mercury called a nonreactive metal?

Mercury is one of the less reactive metals because it does not react with most elements that metals generally react with. For instance, mercury will not react with oxygen except under high temperatures above 662°F (350°C).

Also, it does not react with acids that do not contain oxygen. While water contains oxygen, mercury does not react with water.


Like many elements, the charge of mercury depends on its oxidation state. As it loses electrons when it forms chemical bonds, it gains a positive charge. The compound mercury forms determine its charge.

For instance, it has a +1 charge in mercurous oxide (Hg2O2) and a +2 charge in mercuric oxide (HgO). Furthermore, the charge influences properties such as the melting point, boiling point, solubility, color, and toxicity as seen above.

You can also learn about the charge of transition metals.

Thanks for reading.