A rock is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition and the way in which it is formed
Explanation:
An equation that consists of same number of atoms on both reactant and product side is known as a balanced chemical equation.
For example, 
Number of atoms on reactant side are as follows.
C = 7
H = 6
O = 3
Number of atoms on product side are as follows.
C = 1
H = 2
O = 3
Therefore, to balance this chemical equation we multiply 
by 8 on reactant side. Whereas we multiply 
by 7 and 
by 3 on product side.
Therefore, the balanced chemical equation will be as follows.
Due to the presence of mobile or moving electrons in an atom they are good conductor of heat and electricity. Thus, the heat conduction and current conduction properties of metals are explained by its mobile electrons.
The other mentioned properties of metal are strength which can be explained by type of bonding within the metals, malleability explains the tendency of metals to be flattened into thin sheets, ductility explains the tendency to be stretched into wires, luster means the surface of metal is shiny and opacity is measure of impermeability that is to what extent they can pass light through them, metals are opaque, can not pass light through them or they are not transparent . All these properties are not because of mobile electrons in metals.
Therefore, correct properties are heat conduction and current conduction.
