Improvement in Food Resources — Science STD 9 — Question

Most of the alpha particles go straight through the foil if it is passed through a thin metal foil. This is due to the reason that:

Meristematic tissues in plants are:

In water, the proportion of oxygen and hydrogen by mass is:

The rate of evaporation decreases with an increase in _________?

Most of the mass of an atom is concentrated in a small region of space called the ..............?

Where do we generally mount the material on the slide:

Two masses m and 2m are dropped from certain height ‘h’. Then on reaching the ground:

When a fire man directs a powerful stream of water on a fire from a hose pipe, the hose pipe tends to go backward. This is an example of Newton's:

Which of the following statements are true for pure substances?

1. Pure substances contain only one kind of particles.
2. Pure substances may be compounds or mixtures.
3. Pure substances have the same composition throughout.
4. Pure substances can be exemplified by all elements other than nickel.

1. (i) and (ii)
2. (i) and (iii)
3. (iii) and (iv)
4. (ii) and (iii)

The nucleus of tritium consists of: