Elements in the same group tend to have very similar properties (D). This is due to the number of valence electrons each group has.
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
Answer:
The equation to show the the correct form to show the standard molar enthalpy of formation:

Explanation:
The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states.
Given, that 1 mole of
gas and 1 mole of
liquid gives 2 moles of HBr gas as a product.The reaction releases 72.58 kJ of heat.

Divide the equation by 2.

The equation to show the the correct form to show the standard molar enthalpy of formation:

Because of the crystal structure of the ice, ice has lower density than liquid water. So the volume of the ice of same mass is greater than water. When melting, the volume will decrease.
Answer:
Atmospheric nitrogen is not heavier than chemical nitrogen, largely because “chemical nitrogen” is ultimately derived from atmospheric nitrogen. On the other hand, you could be asking why the atomic mass of nitrogen is not the same as the mass of nitrogen gas; that's because gaseous nitrogen is diatomic, .
Explanation:
This is from Google.
Hope this helps :))