Water — CHEMISTRY STD 9 — Question

Why group 17 elements are highly reactive?

Under what conditions can hydrogenbe made to combine with sulphur?
Name the products and write the equation for the reaction.

Which test will you carry out to find out if a given solution is saturated or unsaturated or supersaturated?

Name the following:
Two atoms having the same number of protons and electrons but different number of neutrons.

(a) Name an element which has one valence electron, but is a non-metal.
(b) Name an element which has two valence electrons, but is a noble gas.

Amongst the metals iron, magnesium, zine and aluminum, which reacts
(a) fastest with dil. sulphuric acid and
(b) slowest with dilute sulphuric acid. Write fully balanced chemical equations.

What happens to the number of valence electrons in atoms of elements as we go down a group of the periodic table?

nitrate which produces brown gas on heating.

Absolute temperature of a gas at 0 °C.