Give some examples of monovalent elements.

Differentiate between the following pair based on the information given in the brackets.

• Cations and anions (formation from an atom)

Consider the elements of group-14. Choose the correct alternative:

a) Si and Ge are semiconductors

b) Carbon and silicon are non-metals

c) Sn and Pb are metals

d) Si and Ge are metalloids

Write symbols of the following elements and the radicals obtained from them, and indicate the charge on the radicals.

Mercury, potassium, nitrogen, copper, sulphur, carbon, chlorine, oxygen.

Which of the following statement(s) is/are True or False?

Statements:

$1$.${\mathrm{H}}_2{\mathrm{SO}}_4$ is used in the refining of petroleum to remove sulfur and other compounds.

$2$. The basic nature of sodium hydroxide ($\mathrm{NaOH}$) is due to hydrogen ions in the solution.