chemistry 3.03 chemical formulas

ionic bonds

  • formed from electrical attraction of two completely oppositely charged ions.

  • contains metal and nonmetal

  • one atom gives electrons to another

covalent bonds

  • forms when atoms share pairs of electrons

  • contains nonmetals

chemical formulas

  • tells how many atoms of each kind of element are in a molecule of a particle compound.

  • ex: formula for hydrogen gas = H2. it means each molecule of hydrogen gas consists of 2 atoms that hydrogen bonded together.

  • another ex: C2H6O means 2 carbon atoms, six hydrogen atoms, and one oxygen atom.

  • if theres no number below a chemical symbol it means 1

  • when you write formulas for molecules that have carbon, hydrogen, and oxygen, do carbon atoms first, then hydrogen, then oxygen.

  • when writing other formulas, write atoms found on left side of period table first.

structural formula

  • sometimes used to represent covalent molecule

  • structural formula shows the arrangement of the atoms and their bonds in a compound molecule.

  • identify location of chemical bonds between atoms of a molecule

writing chemical equations

  • describes a chemical reaction using symbols and numbers

  • written from left to right

  • shows relationship between reactants on left side and the ride side, products, of an equation.

  • arrow sign is basically equal sign

  • ex: C+O2 (reactants) → CO2 (product)

polymer:

  • covalently bonded molecule that has repeating chemical units

  • units can form long chains

  • each repeating unit = monomer

  • monomers are like bricks that make up a wall of polymers