Arrange the first ionization enthalpies of Na, Mg, Al, and Si in ascending order:

1. Na < Mg > Al < Si

2. Na > Mg > Al > Si

3. Na < Mg < Al < Si

4. Na > Mg > Al < Si

Electronic configuration of chalcogens in their outermost orbit is:

1. s² p³

2. s² p⁴

3. s² p⁵

4. s² p⁶

Which of the following is smallest in size?

1. Na⁺

2. F^–

3. O^2–

4. N^3–

When a neutral atom is converted into a cation,there is

1. Decrease in the atomic number

2. An increase in the atomic number

3. An increase in size

4. A decrease in size

Which of the following statements accurately describes the electron affinity trend among halogens?

1. Br > F

2. F > Cl

3. Br > Cl

4. F > I

Which one of the elements has highest ionisation energy?

1. [Ne] 3s² 3p¹

2. [Ne] 3s² 3p²

3. [Ne] 3s² 3p³

4. [Ar] 3d¹⁰ 4s² 4p²

The electronegativity of the following elements increases in the order:

1. C, N, Si, P

2. N, Si, C, P

3. Si, P, C, N

4. P, Si, N, C

Which of the following has the highest electron affinity?

1. F^–

2. O^–

3. O

4. Na

The correct order of the decreasing ionic radii among the following isoelectronic species is:

1. Ca²⁺ > K⁺ >S^2–> Cl^–

2. Cl^– > S^2– > Ca^2– > K⁺

3. S^2– > Cl^– > K⁺ > Ca²⁺

4. K⁺ > Ca²⁺ > Cl^– > S^2–

The correct order of second ionisation energies of B , C , N & O is: 

1. O > N > C > B

2. O > C >N >B

3. O > B > C > N

4. O > N > B > C