The Language of Chemistry — CHEMISTRY STD 9 — Question

State Four characteristics of a chemical change.

If electrons are getting added to en element Y; then
What charge will Y migrate to during the process of electrolysis?

Select the odd one out and justify your answer.
Fe, Zn, Cu and Mg

Name an element which does not contain neutron.

For laboratory preparation of hydrogen, give the following:
chemical equation

Name the substance which makes water temporarily hard

Name and state the following with reference to the elements of the first three periods of the periodic table.
Metalloid in Period 3.

The molecular theory states that the pressure exerted by a gas in a closed vessel results from the gas molecules striking against the walls of the vessel. How will the pressure change if

1. The temperature is doubled keeping the volume constant
2. The volume is made half of its original value keeping the T constant