Chemistry is the branch of science that deals with the study of matter, its properties, how and why substances combine or separate to form other substances, and how substances interact with energy. It is often referred to as the central science because it connects other sciences, such as physics, biology, and earth sciences, to each other.

Matter is any substance that has mass and takes up space. It is the fundamental component of the universe and can exist in several states: solid, liquid, gas, and plasma. The properties of matter can be physical, such as color, melting point, and density, or chemical, such as flammability and reactivity with other substances.

Change is an integral concept in chemistry. Chemical changes involve the transformation of one substance into another, which means new substances with different properties are formed. This is often accompanied by changes that cannot be easily reversed, such as changes in energy, color, or the release of gas. Physical changes, on the other hand, do not alter the chemical makeup of a substance but change its form, like ice melting to water.