NEET Classification of Elements and Periodicity in Properties — Set 10

Question 1

Which element in group 18 has the largest atomic radius?

Accepted Answer

Atomic radius increases down a group. Among He, Ne, Ar, and Rn (group 18), Rn (period 6) has the largest radius.

Question 2

Which element in the fifth period has the highest second ionization enthalpy?

Accepted Answer

Second ionization enthalpy peaks when removing an electron from a stable $\ce{X+}$ ion. Rb (after losing one electron, becomes $\ce{Rb+}$ with $1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 4p^6$) has the highest value in period 5.

Question 3

Which of the following elements forms a basic oxide?

Accepted Answer

Basic oxides are formed by metals, especially on the left side of the periodic table. K (group 1) forms $\ce{K2O}$, a basic oxide, while C, S, and P form acidic or amphoteric oxides.

NEET Chemistry: Classification of Elements and Periodicity in Properties — Practice Set 10

Q1. Which element in group 18 has the largest atomic radius?

Q2. Which element in the fifth period has the highest second ionization enthalpy?

Q3. Which of the following elements forms a basic oxide?

Q4. Which oxide is acidic in nature?

Q5. How many elements are present in the sixth period of the periodic table?

Q6. Arrange the following ions in order of increasing ionic radius: \(\ce{F^-}\), \(\ce{Na+}\), \(\ce{Mg^2+}\).

Q7. Which element in the fourth period has the highest boiling point among d-block elements?

Q8. Which of the following carbonates has the highest thermal stability?

Q9. Which element in the third period has the highest third ionization enthalpy?

Q10. Which of the following has the highest second ionization enthalpy?