**1. Introduction**

Mercury (Hg) is an element like lead or arsenic, and it is classified as heavy metal. It is the only metal present in liquid form as shown in **Figure 1**. It has many interesting properties. The most important properties was listed in **Table 1**.

Mercury is a naturally occurring mineral found primarily in a mineral called cinnabar, which can contain up to 86 percent mercury. It is released through natural rock weathering and (or) volcanic activity [2].

Metallic mercury is used in the production of chlorine gas and caustic soda, and it is also used in thermometers, dental fillings, and batteries. Mercury salts are sometimes used in skin-lightening creams and as antiseptic creams and ointments [3].

### **1.1 Facts about mercury**


#### **Figure 1.** *Drops stock of mercury.*


### **Table 1.**

*Some of the important properties of Hg [1].*


e.Many chemical forms in the air, water, sediment, and living organisms
