Periodic Classification of Elements — Science STD 10 — Question

Name two effects produced by the atmospheric refraction.

Which gland secretes the growth hormone?

A ray of light is incident normally on a plane mirror. What will be the:

1. Angle of incidence?
2. Angle of reflection?

What happens when vegetable oils are hydrogenated? Name the catalyst used.

State three reasons (of which at least one must be chemical) for believing that sulphur is a non-metal.

The following questions are about the nuclear reactor of a power plant.
What is the function of boron rods in the nuclear reactor?

In the reactor of a nuclear power plant, name the material which is used:
As a moderator.

Two solutions A and B have pH values of 3.0 and 9.5 respectively. Which of these will turn litmus solution from blue to red and which will turn phenolphthalein from colourless to pink?

A ray of light strikes a plane mirror such that its angle of incidence is 30°. What angle does the reflected ray make with the mirror surface?

When a solution is added to a cloth strip treated with onion extract, then the smell of onion cannot be detected. State whether the given solution containsan acid or a base.