Mg gained mass because it went from being a single element (on the reactant side) to being a molecule (on the product side).
Answer:
v = 658.82 km/h
Explanation:
The distance between New York and London is 
Time taken from New York to London is 8.5 hours
We need to find the average speed of the plane.
Total distance covered divided by the total time taken is equal to the average speed of an object. So,

So, the average speed of the plane is 658.82 km/h.
The answer should be Pure substance
The oxidation state, sometimes referred to as oxidation number, describes the degree of oxidation of an atom in a chemical compound.
<u>Explanation:</u>
The oxidation number of an atom is the charge that atom would have if the compound was composed of ions. 1. The oxidation number of an atom is zero in a neutral substance that contains atoms of only one element. The oxidation number of simple ions is equal to the charge on the ion.
The oxidation number of a mono atomic ion equals the charge of the ion. The oxidation number of H is +1, but it is -1 in when combined with less electro negative elements. The oxidation number of O in compounds is usually -2, but it is -1 in peroxides. The oxidation number of a Group 1 element in a compound is +1.
The way to working out the numbers is to increase the measure of HNO3 required by the molarity to discover what number of moles you require: 0.115. You ought to have the capacity to make sense of the recipe weight H is 1, N is 14, O is 16. The result of the quantity of moles duplicated by the recipe weight ought to give an esteem in grams. You can utilize the thickness to change over to a volume of HNO3 to add to the right volume of water.