Question

Which of the following two metals will melt at body temperature (${377^0}C$)?
Gallium, Magnesium, Caesium. Aluminium.

Answer 1

Hint:There are two metals that are liquid at the technically designated room temperature or 298 K (${25^0}C$) and they are bromine and mercury and there are total of six elements that can be liquids at actual room temperatures and pressures.

Complete answer:
Room temperature is a loosely defined term that can mean anywhere from ${20^0}C$to ${29^0}C$. For science, it's usually considered to be either ${20^0}C$ or${25^0}C$.
Cesium having the symbol Cs and atomic number 55, is a soft metal that violently reacts with water, and melts at 301.59 K. The low melting point and softness of francium and cesium are a consequence of the size of their atoms. In fact, cesium atoms are larger than those of any other element.
Gallium having the symbol Ga and the atomic number 31 is a grayish metal and melts at 303.3 K. Gallium can be melted by body temperature, as in a gloved hand.
In these given metals, the two metals which melt at body temperature are Gallium and Cesium.
Melting point of Gallium is ${29.7^0}C$
 Melting point of Caesium is ${28.9^0}C$
These two metals have melting points nearer to \[{37^0}C\].

Therefore, the correct answer is Gallium and Caesium.
Note:
Other than Gallium and Cesium, Francium and Rubidium can melt at body temperature. Francium having symbol Fr and atomic number 87 is a radioactive and reactive metal, melts around 300 K. Francium is the most electropositive of all the elements. Although it's melting point is known, there is so little of this element in existence that it's unlikely you'll ever see a picture of this element in liquid form.