PHYSIOLOGY - MARIEB 11E

CONCEPT: FUNDAMENTAL CHEMISTRY Atoms: ● All matter is made of atoms. Atoms contain protons, neutrons, electrons. □ Protons= (+) charge □ Neutrons= 0 charge □ Electrons= (-) charge □ Atoms start with protons=electrons, so that they are neutral—no net _______________________. ● Atoms can gain or lose electrons to other atoms. When this happens, they become charged, and are called ions. □ An anion is an atom that has gained an electron—it’s a negative ion. □ A cation is an atom that has lost an electron—it’s a positive ion. □ A salt is an electrically-neutral compound formed by ionic bonds between cations and anions. EXAMPLE: Sodium (Na+) and Chloride (Cl- ) ions come together to form the salt sodium chloride (NaCl) Na+ + Cl- à NaCl