Answer:

Explanation:
Chemical Equations are representations of chemical reactions in terms of the symbols and formulae of the elements and compounds involved. A chemical equation usually have the reactant at the left hand side while the product is on the right hand side.
A chemical Equation is of little or no value if is not in balanced equation. When an equation is balanced , the total number of atoms of any element on the left-hand side of it must be equal to the total number of atoms of that element on the right hand side.
in the given question; we are given a word problem of chemical symbol to compute and also to balance the chemical equation.
From below; the chemical equation can be written as:

From the above equation we will notice that it is not truly balanced ; so th balanced equation can be written as:

Answer:
Cement is a combination of calcium, silicone, aluminum, iron and lots of other ingredients to make side walks, home made crafts, etc. The person who invented concrete is Joseph Aspdin.
Explanation:
Their weights could be different.
Their volumes could be different.
Their densities could be different.
The volume for an ounce of lead is much different than an ounce of aluminum.
the weight of a cubic meter of balsa wood is much different (and much lighter) than a cubic meter of water. That's why the ancients used balsa for their rafts.
Both. Every nucleotide has a sugar, a nitrogenous base, and a phosphate group