In models of molecules, gray spheres are carbon atoms, white spheres are hydrogen atoms, red spheres are oxygeb atoms, and blue spheres are nitrogen atoms. Which model represents an element?

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

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error