Questions

Fischer projections were originally proposed for the depiction of carbohydrates and used by chemists, particularly in organic chemistry and biochemistry.A Fischer projection always uses an eclipsed conformation. A Newman diagram can represent either an eclipsed conformation or a staggered conformation or a skew conformation.

It is the friction between the feet and the ground that helps us to walk. Without this friction we would slip and fall

The Surface tension pulls the surface of the drop equally at all points thus produces the spherical shape having the minimum surface area. This surface tension is the "skin" of a body of water that makes the molecules stick together.

Hygrometer is used for measuring humidity of air.