Which of the following gases is of brown colour?

Write the electron dot structures of magnesium and chlorine and show the formation of magnesium chloride by the transfer of electrons.

When a metal $X$ is treated with cold water,it gives a basic salt $Y$ with molecular formula $XOH$ (Molecular mass $= 40$) and liberates a gas $Z$ which easily catches fire. Identify $X, Y, Z$.

State whether the following statement is true or false:
The elements or compounds,which occur naturally in the earth's crust,are known as minerals.

An element $A$ is soft and can be cut with a knife. It is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following:

Solder is an alloy of lead and tin. It has a: