Chemistry of Life
Periodic table of elements
Examples??
Aluminum – as in aluminum foil
Oxygen – as in the oxygen we breathe in air
Sodium – as in table salt
Neon – as in neon signs
Gold and silver – as in… you know, gold and silver…
Vocabulary Atom Smallest unit of matter Cannot be broken down Greek atomos means “unable to be cut”
Vocabulary Element Pure substance made of only one type of atom Different elements are found on the periodic table Example: pure gold is made of many gold atoms
Vocabulary Not all of the matter in the world is pure – made of only one element For example, there is no “water” element A group of atoms combined together is a molecule A group of atoms held together by bonds
A molecule of water (H2O) Hydrogen atoms Oxygen atom
In a molecule, atoms are held together by bonds
Types of bonds Covalent bond Ionic bond bond formed by the sharing of one or more electrons, between atoms (need to add something about C forming 4 and that leads to large molecules) Ionic bond Bond formed by one atom giving away electron to another atom No sharing
Types of bonds Hydrogen bond Bond formed when a positive (+) hydrogen atom of one molecule is attracted to a negative (-) atom of another molecule. Creates partially + and partially - ends + - + - + +