What is density? How is it calculated, if the mass and volume of an object is known?
Density is a measurement of the amount of mass a substance has for a given volume. For example, if you have a cube of wood, and a cube of iron, each 1 cm per side, the iron cube would have more mass because it has a higher density. To calculate density, divide the mass by the volume. 23. What determines whether one substance will float on top of another substance? Substances with less density float on top of substances with more density. Wood has a density of 0.5 g/cm3, while water has a density of 1.0 g/cm3. Wood floats on water because its density is lower. 24. Distinguish between an exothermic and an endothermic reaction. In which reaction is heat a product? In which reaction is heat a reactant? An exothermic chemical reaction is a reaction which produces heat as a product. An endothermic chemical reaction is a reaction in which heat is absorbed. Heat is one of the reactants in a endothermic reaction. 25. Identify which of the following chemical equations is endothermic or exothermi
