Which sample equation best illustrates the Law of Conservation of Mass? A. 12 grams reactant X + 10 grams reactant Y → 2 grams product Z + 7 grams product K
B. 5 grams reactant E + 5 grams reactant F → 20 grams product G + 5 grams product H
C . 10 grams reactant Q + 9 grams reactant R → 90 grams product S + 90 grams product
D . 20 grams reactant U + 3 grams reactant V → 23 grams product W

D . 20 grams reactant U + 3 grams reactant V → 23 grams product W

Explanation:

Law of conservation of mass states:

The mass of a closed system (As a reaction), is neither created or destroyed.

That is, the mass of reactants is equal to mass of products.

A. In reaction A 22g of reactants produce 9g of products. This reaction doesn't illustrates the law of conservation of mass.

B. 10g reactant produce 25g of products. This reaction doesn't illustrates the law of conservation of mass.

C. 19g of reactants produce 180g of products. This reaction doesn't illustrates the law of conservation of mass.

D. 23g of reactants produce 23g of products. -This is the reaction that best illustrates the Law of Conservation of Mass.

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.