Answer:
The correct option is;
D. All the elements in families 1 and 2 can place all their shell electrons in the s sub-level
Explanation:
The elements in families 1 and 2 also called the group 1A and group 2A elements are known as the alkali and alkaline earth metals. The elements in the families 1 and 2 are also referred to as the s-block elements as they have their valence electrons which are 1 and 2 respectively, in the s-orbital or s sub-level
Due to their low ionization energy, and the ease with which they donate their valence electrons, elements of the families 1 and 2 are known to be very reactive, and are found in a combined state in nature.
The balanced equation for the above reaction is as follows;
C + H₂O ---> H₂ + CO
stoichiometry of C to H₂O is 1:1
1 mol of C reacts with 1 mol of H₂O
we need to find which is the limiting reactant
2 mol of C and 3.1 mol of H₂O
therefore C is the limiting reactant and H₂O is in excess.
stoichiometry of C to H₂ is 1:1
then number of H₂ moles formed are equal to C moles reacted
number of H₂ moles formed = 2 mol
A.3 moles H2
1 mole N2
I think it is correct
Answer : The correct option is, (C) 6
Explanation :
Oxidation-reduction reaction : It is a reaction in which oxidation and reduction reaction occur simultaneously.
Oxidation reaction : It is the reaction in which a substance looses its electrons. In this oxidation state increases.
Reduction reaction : It is the reaction in which a substance gains electrons. In this oxidation state decreases.
The given unbalanced chemical reaction is,

Half reactions of oxidation and reduction are :
Oxidation :
......(1)
Reduction :
.......(2)
In order to balance the electrons, we multiply equation 1 by 2 and equation 2 by 3, we get:
Oxidation :
......(1)
Reduction :
.......(2)
The overall balanced chemical reaction will be:

From this reaction we conclude that the electrons are getting transferred from iron to iodine and the number of electrons transferred are 6 electrons.
Hence, the correct option is, (C) 6