TEAS Science - Chemistry

Matter Anything that takes up space and has mass Mass Quantity of matter an object has Elements Substances that cannot be broken into simper types of matter Atom Smallest part of an element that still retains all the original properties of the element Atom Includes: - Protons - Electrons - Neutrons Protons - Positively charged subatomic particle - Found in the nucleus of an atom - Number distinguishes one atom from another Neutrons - Neutral subatomic particles - Found in the nucleus of an atom Electrons - Negatively charged subatomic particles - Found in various energy levels (orbital shells) around the nucleus Atomic Number - The number of protons in the nucleus of an atom - Serves as an ordering device for the periodic table Atomic Mass The total number of protons and neutrons in the nucleus of an atom Isotopes - Atoms with the same number of protons, but different numbers of neutrons. - Every element is found to have multiple - Ex. Carbon has three Catalysts - Enzymes that control the rate of chemical reactions - Reaction rates can be increased by the use of promoters or decreased by use of inhibitors Enzymes - Biological catalysts that increase the rate of chemical reactions - Most are proteins Activation Energy The amount of energy required for a reaction to proceed Enzymes - Are driven by temp, pH, and substrate concentration - Are protein molecules composed of amino acids - Are highly selective - Lower activation energy - Its shape is important to its function pH - Is a measure of hydrogen ion (H+) concentration within a solution Substrate A molecular surface acted upon by an enzyme Ionic Bond - A relationship between two oppositely charged atoms - Results when one or more electrons from an atom are transferred (not shared) to a second atom