What do a mole of magnesium (mg) and a mole of iron (fe) have in common

they have the same number of atoms.

Explanation:

1) Mole is a basic unit of the SI (international system of measurements) used to measure the amount of a substance.

2) Mole is a fixed value and it is defined as the number of atoms in 12.000 grams of the isotope carbon - 12.

3) That approximate value of a mole is 6.022 × 10 ²³.

That means that both a mole of magnesium (Mg) and a mole of iron (Fe) (such as a mole of any element) have the same number of atoms which is about 6.022 × 10 ²³.

4) A more precise value for the mole is 6.0221367 × 10 ²³, but 6.022 × 10 ²³ is quite precise for most calculations in chemistry.

5) This number is known as Avogadro's number, in honor to the chemist (and lawyer) Amadeus Avogadro who in 1811 determined the number of a mole of gas.

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solute : a solute is a substance that is dissolved in another substance is known as a solvent. it is mixed with a special mixture know as homogeneous mixture.

solvent: a solvent is a substance that dissolved a solute, which results in a solution is known as solvent.