Elements of group IB and IIB are called:
(a) normal elements
(b) transition elements
(c) alkaline earth metals
(d) alkali metals
The outer electron configuration of Gd (Atomic no. 64) is:
(a) 4f3 5d56d2
(b) 4f8 5d106d2
(c) 4f4 5d46d2
(d) 4f7 5d16s2
The radius of La3+ (at. no. 57) is 1.06 The radius of Lu3+ (at.no. 71) might be:
Which of the following transition metal ions has the lowest density?
Ionic radii are
(a) inversely proportional to effective nuclear charge
(b) inversely proportional to square of effective nuclear charge.
(c) directly proportional to effective nuclear charge
(d) directly proportional to square of effective nuclear charge
Which one is a metalloid?
Zn and Cd do not show variable valency like 'd' block elements due to :
(b) Completed 'd' orbital
(c) two electrons in outermost orbit
(d) low m.p.