18
MCQ (Multiple Correct Answer)
Which of the following elements can show covalencey greater than 4 ?
A
Be
B
P
C
S
D
B
19
MCQ (Multiple Correct Answer)
Those elements impart colour to the flame on heating in it, the atoms of which require low energy for the ionisation (i.e., absorb energy in the visible region of spectrum). The elements of which of the following groups will impart colour to the flame ?
A
2
B
13
C
1
D
17
20
MCQ (Multiple Correct Answer)
Which of the following sequences contain atomic numbers of only representative elements?
A
$3,33,53,87$
B
$2, 10, 22, 36$
C
$7,17,25,37,48$
D
$9,35,51,88$
21
MCQ (Multiple Correct Answer)
Which of the following elements will gain one electron more readily in comparison to other elements of their group?
A
$\mathrm{S}(\mathrm{g})$
B
$\mathrm{Na}(g)$
C
$\mathrm{O}(\mathrm{g})$
D
$\mathrm{Cl}(\mathrm{g})$
22
MCQ (Multiple Correct Answer)
Which of the following statements are correct?
A
Helium has the highest first ionisation enthalpy in the periodic table
B
Chlorine has less negative electron gain enthalpy than fluorine
C
Mercury and bromine are liquids at room temperature
D
In any period, atomic radius of alkali metal is the highest