Which properties change the composition of a substance? Ex. H20 breaks down into 2 Hydrogen and 1 Oxygen atom. chemical properties

physical properties

chemical and physical properties

neither chemical nor physical properties

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?

The density of benzene at 15 °c is 0.8787 g/ml. calculate the mass of 0.1500 l of benzene at this temperature. enter your answer in terms of grams

Which is an example of a reversible physical change?