In the reaction of magnesium with oxygen gas, a considerable amount of energy was released. this is an example of an exothermic reaction. from this evidence what can you conclude about the energy stored in the reactants compared to the energy stored in the product? what other examples of exothermic reactions did you observe? re-write the balanced equation for the reaction of mg and o2, this time with the term "+ energy" on the appropriate side of the equation.

-the reactants have more energy stored because you didn't get a great amount ( if any ) of energy released after the reaction was complete.

-Mg + O2 = MgO + energy

it should be p1 v1 = p2 v2

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.