Again with the questions from my test, all help is appreciated.

The atomic number will remain the same because a proton has a positive charge and a electron has a negative charge so they would cancel each other out

the law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products. because atoms are only rearranged in a chemical reaction, there must be the same number of sodium atoms and chlorine atoms in both the reactants and products

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.