AP Biology Exam Review 2023-24 with 100% correct answers

Matter - anything that takes up space and has mass Element - A substance that cannot be broken down into simpler substances Compound - A substance made up of atoms of two or more different elements joined by chemical bonds Molecule - two or more atoms held together by covalent bonds Trace elements - An element indispensable for life but required in extremely minute amounts. Atom - Basic unit of matter Neutron - A subatomic particle that has no charge and that is found in the nucleus of an atom Protons - positively charged subatomic particles found in the nucleus. Electron - A subatomic particle that has a negative charge and is found outside the nucleus Atomic number - number of protons Mass number - the sum of the number of neutrons and protons in an atomic nucleus Isotopes - Atoms of the same element that have different numbers of neutrons Potential energy - stored energy that results from the position or shape of an object Kinetic energy - the energy an object has due to its motion Valence electrons - Electrons on the outermost energy level of an atom Covalent bonds - Bonds created by sharing electrons with other atoms.