Electron (e - ) orbit/energylevel Proton (p + ) Neutron (n 0 ) nucleus

# of p + p + + n 0

Diatomic Elements: Elements that are most commonly found in a covalent bond with itself. I Have No Bright Or Clever Friends I 2 H 2 N 2 Br 2 O 2 Cl 2 F 2

H : neutral atom H + : positive ion H - : negative ion Atoms can either gain or lose electrons Gain - negatively charged ion. Loses - positively charged ion

Deuterium Atomic Mass = 2 Atomic Number = 1 Hydrogen Atomic Mass = 1 Atomic Number = 1 Atoms that have the same number of protons but a different number of neutrons are called Isotopes.

Octet rule: atoms react to acquire a full outer shell: Give away an e - to another atom. Take an e - from another atom. Share an e - with another atom. Ionic bond Covalent bond An ION is an atom that has lost or gained an electron. Lose e - – positive ion OR cation. (metals) Gain e - – negative ion OR anion. (nonmetals)

Ionic NaCl A compound has different characteristic properties than the atoms which form it. Covalent HCl

Chemical formula gives the following information: · The different elements in the compound. · The number of atoms in the compound.

Writing Rule 1: Write the symbol of the metallic element first. Be Cl Rule 2: Place the combining capacity of one element as a subscript of the other element. Beryllium combines with Chlorine

Rule 3: Leave subscripts with a value of 1 out. Be Cl 21 Two Naming rules: 1.Write the full name of the metal ion first. 2.Name the non-metal ion dropping the last part of the name and adding the suffix “ide”. berylliumchloride

Rule 4: Reduce the subscripts if possible. Mg S Magnesium combines with Sulfur Mg S magnesiumsulphide

Transition metals can give away different numbers of electrons. To avoid confusion: Brackets are used to show how many electrons the Transition metal is giving away.

Iron (III) chloride Iron (II) chloride Fe Cl FeCl 2 Fe Cl FeCl 3

Write the name of the ionic compound: PbO lead oxide(IV) +4-2

Covalent Compound: Contain two or more NON-METAL atoms. Formed by SHARING valence electrons to fill outer shell – octet rule.  A molecule is the smallest unit of a covalent compound. Non-metal + Non-metal = covalent bonding

PrefixNumber of Atoms mono1 di2 tri3 tetra4 penta5 hexa6 hepta7 octa8 nona9 deca10

Step 1: first non-metal is named with a prefix to show the number of atoms. We do not use “mono” for the first non-metal. nitrogen oxide N O Step 2: second non-metal is named with a prefix AND with the “ide” ending. di 24 tetra dinitrogen tetroxide Prefix Number of Atoms mono1 di2 tri3 tetra4 penta5 hexa6

Writing formulas Step 1: Write the symbol of each element. Step 2: Use a subscript to show the number of each type of atom given by the prefix. Do not reduce covalent formulas. phosphorus oxide P O di 2 5 penta Prefix Number of Atoms mono1 di2 tri3 tetra4 penta5 hexa6