Atomic Structure and Chemical Bonding — CHEMISTRY STD 9 — Question

Name the sub-atomic particle whose charge is -1.

Name and state the following with reference to the elements of the first three periods of the periodic table.
Bridge elements of Period 3 of Group 1,2and 3.

Which period is (a) shortest (b) longest in the long form of periodic table? How many elements are in (a) and (b)?

Identify the gases from the observations:
A colourless gas which fumes strongly in air and has a sharp smell. It gives dense white fumes with a glass rod dipped in conc. HCl.

How are X-rays produced?

Name the sub-atomic particle whose charge is 0.

Write the balanced chemical equation of the following reaction.
ammonia+oxygen → nitric oxide+water

Give the name of the element and number of atom of those elements present in the following compound.
Ammonia

Name any two:
Natural sources of atmospheric pollution.