Answer:
A. Felsic igneous rocks are less dense than mafic igneous rock
Explanation:
"Felsic rocks are composed of larger quantities of silicates and therefore are less dense. Felsic magma is less dense and more viscous than mafic magma." - study.com
The study of plants, plant life cycles, photosynthesis, plant parts, etc. is under botany (study of plants).
The balanced chemical reaction is written as:
<span>2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g)
We are given the amount of acetylene to be used in the reaction. This will be the starting point for the calculations.
20.0g C2H2 ( 1 mol / 26.04 g) ( 5 mol O2 / 2 mol C2H2 ) ( 32 g / 1 mol ) = 61.44 g O2 is needed</span>
Those are called as element
The residue of coal decomposition in the manufacture of steel is coal tar. It is a by product of the coking process in the blast furnace. Coal gas is another by product but is not the answer becuase this is not a residue which is a solid. Coal gas is a gas. Coke in fact is one of the reactants fed for steel making. Answer is choice 3.