A physical change is when the physical properties of a substance have changed, but the make up (formula) of the substance does not change. For example, water changing to ice is a physical change. The physical properties of ice (such as density, hardness, index of refraction) are different...
To describe the atomic makeup of compounds, chemists use systematic methods for naming compounds and writing chemical formulas. In this chapter, you will be introduced to some of the rules used to identify simple chemical compounds. MAIN IDEA Formulas tell the number and kinds of atoms in a...