Review

Grade11 Chemistry Course Review Unit1 - Matter and Chemical Bonding Atomic(原子的) Structure; Isotopes(同位素) and Radioisotopes(放射性同位素) Atomic Structure Composition of an Atom: Particle(粒子) Charge(电荷) Mass(质量) Role Proton(质子)(p) $ +1e $ $ 1.67 \times 10^{-27} kg $ Defines the element Neutron(中子) (n) $ 0 $ $ 1.67 \times 10^{-27} kg $ Determines isotopes Electron(电子) (e) $ -1e $ $ 9.1×10^{-31} kg $ Participate in Chemical Bonds(化学键) and Reactions $ e=1.6×10^{-19} C $ $ ^{A}_{Z}X $ Neutron Number ($ N $) Atomic Number ($ Z $) Mass Number ($ A $): $ Z + N $ (e.g., oxygen-16: $ 8p + 8n \to A=16 $) Ground State(基态): The electrons(电子) in a atom occupies the lowest energy levels , making it stable and non-radiative. ...