Answer:
They are called homogenous mixtures. If you put sand into a glass of water, it is considered to be a mixture. You can always tell a mixture, because each of the substances can be separated from the group in different physical ways. You can always get the sand out of the water by filtering the water away.
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:
The IUPAC name of the compound has already been given which is 2,2-dimethyl-4-ethylheptane.
Explanation:
The IUPAC (International Union of Pure and Applied Chemistry) is an authority in chemistry that provides a guideline and standardized methods in the naming of compounds formed from the periodic table.
In order the give an IUPAC name to a compound, certain steps needs to be followed, these includes:
--> Identify the functional group in the compound as this will form the suffix. For example if the functional group is an alkane the suffix will be -ane.
--> Identify the longest carbon chain (it may not be a straight chain) that contains the functional group. This forms the prefix. Example: if the longest carbon chain is 7 carbon atoms then the prefix will be hept-
--> All the carbons of the longest chain should be numbered
--> Identify branched groups on the chain and name them according to the number of carbon atoms. They usually end with -yl.
--> Finally, combine the elements of the name is a single word.
The structural formula of the IUPAC compound can be found in the attached file for a better understanding. The branched groups are circled.