CONCEPT: FUNDAMENTAL CHEMISTRY -BASIC CHEMISTRY

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 Bonding and Polarity: ● A covalent bond is when 2+ atoms share electrons and become bonded together. □ All the atoms covalently bonded together make up a _______________________. ● A molecule’s electrons may be distributed evenly or unevenly across it. This distribution often determines its shape. □ Nonpolar molecules (or nonpolar portions of large molecules) have charge pretty evenly distributed. - Carbons and Hydrogens bonded together tend to be nonpolar. □ Polar molecules (or polar portions of large molecules) have charge unevenly distributed across the molecule. - Heteroatoms (N, O, P, S) tend to be polar. EXAMPLE: Water is polar, with electrons creating a partial negative charge around the O atom. Hexane is nonpolar. PHYSIOLOGY - MARIEB 11E CH. 2 - BASIC CHEMISTRY Page 2 Intermolecular Forces (Non-Covalent Bonds): ● 2+ molecules may also interact and be attracted to each other via intermolecular forces (aka no