Answer : The correct option is, (C) 2, 4 and 5.
Explanation :
Combustion reaction : It is a type of reaction in which a hydrocarbon react with an oxygen molecule to give carbon dioxide, water as a product.
For example : Methane react with oxygen to give carbon dioxide and water.

In the given list of chemical substances,
are in oxide form. They can not be both reactant and product of a single combustion reaction.
In the given list,
is the only hydrocarbon which shows a combustion reaction. That means
react with
to give
and
as a product.
The balanced combustion reaction of
is,

Therefore, the correct answer is, (C) 2, 4, and 5.
Great amounts of atomic energy are released when
a _______reaction occurs.
Great amounts of atomic energy
are released when a chemical reaction occurs. The process can be an exothermic reaction
or endothermic reaction depending on the substances involved in the reaction.
Using the significant figure it would be 27.3
Answer: D
Explanation:
the atom of the metal loses one electron which becomes delocalised and is attragted by the positive nucleus leading to formation of metallic bond.

a)



b)


Using the atomic mass given in the periodic table:




c)


Using the atomic mass given in the periodic table:




This result is an aproximation.