Question

In which of the following pair size of 1st element is higher as compare to 2nd :-
(1) Zn, Sc
(2) Sc, La
(3) Cu, Ag
(4) La, Hf​

Answer 1

Answer:

Cu, ag is the right answer

Answer 2

(4) La, Hf is the correct answer.

• La is the symbol that stands for chemical element Lanthanum. The atomic number is 57.
• Hf is the symbol that stands for chemical element Hafnium. The atomic number is 72.
• There are extra 14 electrons in f subshell, which do not provide enough screening effect.
• This results in decreased atomic radii due to increased nuclear charge.
• Thus Hafnium is smaller than Lanthanum.