Basic Chemistry for Earth Science

The Periodic Table Family/Group: vertical columns Period: the horizontal rows on the periodic table

Elements are pure substances that cannot be broken down into a more simple substance. They are found on the periodic table. An atom is the smallest part of an element you can have and still have the properties of that element. All atoms are make-up of subatomic particles. The 3 subatomic particles are: Protons Neutrons Electrons

The nucleus is the center of an atom. Protons have a positive charge and are found in the nucleus. Electrons have a negative charge and are found in a “cloud” outside of the nucleus. Neutrons are neutral and are found in the nucleus.   The number of protons determine the identity of an element. The Atomic Number tells you the number of protons and electrons (unless it is an ion). The Mass Number tells you protons + neutrons. Neutrons = Mass Number - # of Protons

Element Mass # Atomic # Protons Electrons Neutrons 24.31 12 26.98 13 Gold 197.0 79 118 Magnesium 24.31 12 Aluminum 26.98 13 Calcium 40.08 20 Sodium 22.99 11

An Isotopes are atoms of an element that have the same number of protons, but a different number of neutrons. Element Mass # Atomic # Protons Electrons Neutrons Carbon 12 6 14 8

A ion is an atom that has gained or lost electrons A ion is an atom that has gained or lost electrons. If an atom loses electrons it is metal. If an atom gains electrons it is non-metal. Element Mass # Atomic # Protons Electrons Neutrons Charge Calcium 40.08 20 18 +2 Chlorine 35.45 17 -1 Nitrogen 14.01 7 10 -3

Metals - Lose electrons easily form positive ions dominates the periodic table do not form ionic bonds with other metal ions Nonmetals Gain electrons easily from negative ions

A compound is two or more elements chemically combined. Examples: Water H2O Table Salt NaCl Baking Soda Na2CO3 Vinegar HC3H3O2 A molecule is the smallest part of a compound that you can have and still have the properties of the compound. A mixture is a material system made up by two or more different substances which are mixed but are not combined chemically.

A covalent bond is a bond formed when electrons are shared. An ionic bond is a bond formed when electrons are either gained or lost from one element to another.

A metallic bond is a bond formed when electrons are shared in large amounts. -like a sea of electrons that are shared by all atoms

Ionic Bonds are like TYRANTS. They take what they want. Covalent Bonds are like socialists. They share what they need. Metallic Bonds are like Anarchists. They run around sharing what they need, but with no thought of ownership.