Chem 403 class 3

Groups

Periods

1 to 7

1 to 8 and letters (A or B)

the main-group or representative elements

transition elements

are located at the bottom and are part of the transition elements

group

period

soft highly reactive metals

Highly reactive metals

Highly reactive nonmetals

gases that aren't very reactive

good conductors of heat and electricity

mostly gases or brittle solids; do not conduct electricity or heat

semiconductors because they conduct electricity but not as well as most metals

generally between metal and a non metal

is an atom or group of atoms that has a net charge because the # of protons doesn't equal the # of electrons

+ charged ions

- charged ions

lose 2 electrons and formed cations with a +2 charge

the nearest noble gas

Ionic compounds consist of anions and cations (which are balanced) so the charge is neutral

• Covalent bonds share electrons and have a charge of neutral
• also want to have hte same number of electrons as the nearest noble gas. This is achieved by sharing.

2 or more atoms bounded together to form an ion

shows the relative number of atoms in a compound

Example: Hydrogen peroxide is HO (1 H for every O)

the actual formula with the correct number of atoms

Example: for Hydrogen Peroxide it is H₂O₂

this shows how the atoms are connected to eachother

Example: hydrogen peroxide is H-O-O-H

Cation first then the anion

• 1. element in the lower group number comes first
• 2. If both elements are in the same group, the one with the higher period is named first
• 3. The 2nd element is named with its root and the suffix "ide"
• 4. Id more than one atom of an element is present, Greek numerical prefixes are used to indicate how many elements are present

add up the atomic masses

ex. CO₂ 1x 12.01 (for 1C) + 2x 16.00 (for 2 Os)