The most abundant metal in the Earth's crust is:

Which of the following waves are used in microwave ovens to heat food?

The process by which solid turns directly into gas without becoming liquid is called:

The deficiency of vitamin B1 causes which disease?

Which of the following gases is used in fire extinguishers?

Which of the following is the lightest gas?

The primary source of energy for most ecosystems is:

The instrument used to measure humidity in the air is:

Which of the following is used in vaccines to build immunity?

Which of the following blood components helps in clotting?

The number of bones in an adult human body is: