Biology Exam 1 MGCCC Questions and Answers 2024/2025

Atomic Number  The Number of Protons in the Nucleus. Cation  Atom with a positive charge (more protons than electrons) Anion  Atom with a negative charge (more electrons than protons) he number of Protons CAN or CAN NOT be changed?  Can NOT (except in stars) electrons  are added as dots, starting on the right, and move clockwise. isotopes  Change in the number of Neutrons ions  Change in the number of Electrons 2 0 2 4 /2025 | © copyright | This work may not be copied for profit gain Excel! 1 | P a g e | G r a d e A + | 2 0 24 / 2 0 2 5 isotopes (contd.)  Neutrons stabilize an atom and keep the protons and electrons from pulling each other apart. When the number of neutrons is changed, the atom destabilizes and becomes radioactive. Uses for Isotopes  Medicine (PET scans, FDA approved isotopes, C14 traces how carbon moves through plants, Radiometic dating..) half life  Time it takes for an atom to lose 50% of its energy covalent bond  electrons are shared ionic bond  electrons are taken hydrogen bond  weak attraction between slightly charged atoms and a hydrogen atom covalent bond example 2 0 2 4 /2025 | © copyright | This work may not be copied for profit gain Excel! 1 | P a g e | G r a d e A + | 2 0 24 / 2 0 2 5  oxygen ionic bond example  salt hydrogen bond example  water H2O  H and 0 share electrons, but not evenly. We call this a Polar Covalent Bond! hydrogen bond (contd.)  weak attraction between a slightly + H, and a slightly -atom on some other