Answers based on the periodic table:
(a) Element with five electrons in the outer subshell:
Elements having five electrons in the outer subshell belong to Group 15 and have the configuration ns2 np3.
Example: Nitrogen (N)
(b) Element that would tend to lose two electrons:
Elements of Group 2 (alkaline earth metals) have two electrons in their outermost shell and tend to lose both electrons to form +2 ions.
Example: Magnesium (Mg)
(c) Element that would tend to gain two electrons:
Elements of Group 16 have six valence electrons and tend to gain two electrons to complete their octet.
Example: Oxygen (O)
(d) Group having metal, non-metal, liquid as well as gas at room temperature:
Group 17 (Halogens) contains elements in different physical states:
• Fluorine and chlorine are gases.
• Bromine is a liquid.
• Iodine shows metallic character in some properties (solid non-metal).
Hence, Group 17 satisfies the given condition.
Conclusion:
Using the periodic table, properties such as valence electrons, tendency to lose or gain electrons, and physical state can be predicted accurately.
Given below are two statements:
Statement (I): According to the Law of Octaves, the elements were arranged in the increasing order of their atomic number.
Statement (II): Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic numbers.
In the light of the above statements, Choose the correct answer from the options given below:
The correct orders among the following are:
[A.] Atomic radius : \(B<Al<Ga<In<Tl\)
[B.] Electronegativity : \(Al<Ga<In<Tl<B\)
[C.] Density : \(Tl<In<Ga<Al<B\)
[D.] 1st Ionisation Energy :
In\(<Al<Ga<Tl<B\)
Choose the correct answer from the options given below :