AP Bio Unit 1 Test 2026 Practice Test , Questions with Correct Answers, A+

What are the four properties of double bonds? Bonds that share two pairs of electrons (four electrons), strong strength, short length, no free rotation and rigidity Ionic Bond Bonding between metals and nonmetals where electrons are exchanged between atoms. Hydrogen Bond An attraction between molecules that occur between hydrogen in one molecule and an electronegative atom of another molecule. Are hydrogen bonds true bonds? No! They are intramolecular forces. Polar Bond The electro negativities of atoms in a molecule are not the same (or very similar), leading to electrons that are not shared equally between the atoms. Non-polar Bond The electro negativities of atoms in a molecule are the same (or very similar), leading to electrons that are shared equally between the atoms. Can some large molecules have one end that is polar and another end that is not polar? Yes In biology, shape = FUNCTION!!! Is energy/charge conserved? Yes Lewis Molecule Model Shows all atoms and bonds. Ball-and-Stick Molecule Model Shows 3D arrangement; atoms = balls, bonds = sticks. Line Model Simplest model. Corners and ends = carbons. Hydrogens bonded to carbons are implied. Water is _____, exhibits ________ and ________, has _______ _______, resists ___________ _______, and acts as the universal _______ polar, cohesion and adhesion, surface tension, temperature changes, solvent Polar molecules (like water) can hydrogen bond with Other water molecules and other polar or charged molecules. Cohesion for water Water molecules are attracted to and can hydrogen bond with other water molecules. Adhesion Water molecules are attracted to and can hydrogen bond with other polar or charged molecules Atoms The smallest unit of matter that has the characteristics of its specific element. Orbitals have different amounts of energy associated with them How does the electron orbital correspond to energy? Electrons closer to the nucleus = less energy = more stable. Electrons father from the nucleus = high energy. Valence Electrons Electrons furthest from the nucleus (in the outermost orbital) Ions Charged atoms What is a positive ion called? cation What is a negative ion called? anion Electronegativity An atom's ability to attract shared electrons in a chemical bond. What the the three important electronegative elements? Fluorine, Oxygen, and Nitrogen What are the important biological elements? Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorus