Match the Column I with Column II and select the correct answer using the codes given below:

	Column I		Column II
A.	Ionic bond	$1$.	$\mathrm{NaCI}$
B.	Covalent bond	$2$.	Diamond
C.	Molecular bond	$3$.	Iodine
D.	Hydrogen bond	$4$.	${\mathrm{NH}}_3$

To meet its rapidly growing energy demand, some opine that India should pursue research and development on thorium as the future fuel of nuclear energy. In this context, what advantages does thorium hold over uranium?

1. Thorium is far more abundant in nature than uranium.

2. On the basis of per unit mass of mined mineral, thorium can generate more energy compared to natural uranium.

3. Thorium produces less harmful waste compared to uranium.

Which of the statement(s) given above is/are correct?

Consider the following statements

1. P-32 is used in blood cancer.

2. Fe-59 is used in detection of disorder in pancreatic gland.

3. Na-24 helps to locate the defect in blood circulations.

4. I -131 is used in detection and cure the disorder of thyroid.

Which of the statement(s) given above is/are incorrect?

Glycerol is viscous and has a high boiling point because:
$1.$ It has a low molecular mass.
$2.$ It forms intramolecular hydrogen bonding.
$3.$ It forms intermolecular hydrogen bonding.

Select the correct answer using the codes below.

All types of electromagnetic radiation have different wavelengths and frequencies but travel at the same speed. The frequency for different wavelengths are around:

1. $106 \mathrm{Hz}$ for radio-frequency

2. $1010 \mathrm{Hz}$ for microwave

3. $1013 \mathrm{Hz}$ for infrared

4. $1015 \mathrm{Hz}$ for visible light

Which of the above is used for radar?