Which of the following statements are true?

A. Unlike Ga, which has a very high melting point, Cs has a very low melting point.

B. On the Pauling scale, the electronegativity values of N and Cl are

Question

Which of the following statements are true?

A. Unlike Ga, which has a very high melting point, Cs has a very low melting point.

B. On the Pauling scale, the electronegativity values of N and Cl are not the same.

C. Ar, \mathrm{K^+}, \mathrm{Cl^-}, \mathrm{Ca^{2+}} and \mathrm{S^{2-}} are all isoelectronic species.

D. The correct order of the first ionisation enthalpies of Na, Mg, Al and Si is Si > Al > Mg > Na.

E. The atomic radius of Cs is greater than that of Li and Rb.

Choose the correct answer from the options given below:

Vishal Gupta · Accepted Answer

B. Ar, \mathrm{K^+}, \mathrm{Cl^-}, \mathrm{Ca^{2+}} and \mathrm{S^{2-}} all have 18 electrons (C true); atomic radius grows down Group 1, so Cs > Rb > Li (E true). Ga in fact has a low melting point (A false); N and Cl share the Pauling value 3.0 (B false); Mg > Al in first ionisation enthalpy (D false). Hence C and E.

Classification of Elements and Periodicity in Properties

More from this chapter in past papers