Indian army has published the notification for SSC Tech 56 men and SSC Tech 27 women for the course commencing at OTA Chennai from April 2021
Which one of the following is not a monoatomic element ?
Copper
Helium
Iodine
Barium
Refer to change in the properties of elements on moving from left to right across a period of the Periodic Table. For each property, choose the correct answer. The electron affinity of the elements in groups 1 to 7:
goes up and then down
decreases and then increases
increases
decreases
Which of the following factor is the most important in making fluorine the strongest oxidizing agent?
Electron affinity
Ionization energy
Hydration Enthalpy
bond dissociation energy
In which pair do both atoms have one electron only in an "s" orbital in their ground states?
Ca,Sc
Cu,Be
H,He
Li,Cr
The electron affinities of B,C, N and O are in the order of _____________.
B < C < N < O
B< C < O > N
B< C > O > N
B > C < O < N
The atom of which of the following elements forms dual closed shell configuration by receiving one electron?
He
H
Li
B
Which of the following will not have 18 electrons?
K+
Cl−
K
Ca2+
How many electron are there in chloride ion?
17
18
16
8
Which of the following statements is not correct for the element having electronic structure 2,8,8,2
Its valency is 2
It is in fourth period
It is in group II
Its atom forms negative ion
Which of the following pair has elements containing same number of electrons in the outermost orbit
N,O
Na,Ca
As,Bi
Pb,Sb
