Rare gases are stable because they
are chemically active
contain equal number of protons and neutrons
contain more electrons than protons
have octet structures
Correct answer is D
They are the most stable due to having the maximum number of valence electrons their outer shell can hold. That means rare gases have the octet configuration.
Which of the following halogens is liquid at room temperature?
lodine
Chlorine
Bromine
Fluorine
Correct answer is C
Bromine is a reddish-brown liquid at room temperature.
In the periodic table all elements within the same group have the same
number of neutrons
number of valence electrons
number of isotopes
atomic number
Correct answer is B
The elements in the same group in the periodic table has the same number of electrons in the outer shell. That means, they have the same number of valence electrons.
The element with electron configuration 1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^1\) belongs to
s-block period 3, group 1
p-block, period 3, group 2
s-block, period 3, group 3
p-block, period 3, group 3
Correct answer is D
1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^1\) = 2, 8, 3.
The element is in period 3 and group 3.
Which of the following arrangements represents the correct order of electronic energy level?
1s 2p 2s 3p 3s 3d 4s
1s 2s 2p 3s 3p 3d 4s
1s 2s 2p 3s 3p 4s 3d
1s 2s 3s 2p 3p 4s 3d
Correct answer is C
The correct order of electronic energy level is OPTION C according to the Aufbau principle.