Classification of Elements and Periodicity in Prop

3.43. Assertion: Their synthesis and characterisation of new elements with very high atomic numbers require highly sophisticated costly equipment and laboratory.

Reason: The new elements with very high atomic numbers are so unstable that only minute quantities, sometimes only a few atoms of them are obtained.

3.42. Assertion: Elements of the same group exhibit similar chemical properties.

Reason: Elements of the same group have similar valence shell electronic configuration.

3.41. Assertion: The size of an anion will be larger than that of the parent atom.

Reason: The addition of one or more electrons would result in increased repulsion among the electrons and a decrease in effective nuclear charge.

3.41. Assertion: The size of an anion will be larger than that of the parent atom.

Reason: The addition of one or more electrons would result in increased repulsion among the electrons and a decrease in effective nuclear charge

3.40. Considering the elements F, Cl, O and N, the correct order of their chemical reactivity in terms of oxidising property is:                                                        

(a) F > Cl> O > N

(b) F > O > Cl> N

(c) Cl> F > O > N

(d) O > F > N > Cl

3.39. Considering the elements B, C, N, F and Si, the correct order of their non-metallic character is:

(a) B>C>Si>N>F

(b) Si>C>B>N>F

(c) F>N>C>B>Si

(d) F>N>C>Si>B

3.38. Considering the elements B, Al, Mg and K, the correct order of their metallic character is:

(a) B>Al>Mg>K

(b) Al>Mg>B>K

(c) Mg>Al>K>B

(d) K>Mg>Al>B

3.37. Which of the following statements is incorrect in relation to ionization enthalpy?

(a) Ionization enthalpy increases for each successive electron.

(b) The greatest increase in ionization enthalpy is experienced on removal of electrons from core noble gas configuration.

(c) End of valence electrons is marked by a big jump in ionization enthalpy.

(d) Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.

3.36. The size of isoelectronic species-F^–, Ne and Na⁺ is affected by

(a) Nuclear charge (Z)

(b) Valence principal quantum number (n)

(c) Electron-electron interaction in the outer orbitals

(d) None of the factors because their size is the same

3.35. Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell?

(a) Valence principal quantum number (n)

(b) Nuclear charge (Z)

(c) Nuclear mass

(d) Number of core electrons