Bell Ringer 10-19-09 Continue working on Chapter 5 Vocabulary in your notebook. (p. 178)
Bell Ringer 10-19-09 Refer to p. 150. What are valence electrons? What do valence electrons determine?
Atoms, Bonding, and the Periodic Table Chapter 5 Section 1 Atoms, Bonding, and the Periodic Table
Valence electrons Valence electrons are those e- on the outer most energy level. The number of valence e- determines many properties of that element, including the ways in which the atom can bond with other atoms.
This is called the octet rule. Happy Atoms Atoms are the most happy, or stable, when they have 8 electrons in their outermost energy level. This is called the octet rule.
Valence Electrons and Groups The elements within a group have similar properties because they all have the same number of valence e- in their atoms. Period = How many Energy Levels Group = Number of Valence Electrons
Electron arrangement The different positions for an electron in an atom are called energy levels. Each energy level represents a different amount of energy. Energy level 1 can hold up to 2 e-. Energy level 2 can hold up to 8 e-. Energy level 3 can hold up to 18 e-. Energy level 4 can hold up to 32 e-.
Group 1 Alkali metals 1 valence e- + 1 charge Group 2 Alkaline earth metals 2 valence e- + 2 charge Group 13 Boron Fam. 3 valence e- +3 charge Group 14 Carbon Fa. 4 valence e- +4/-4 Group 15 Nitrogen Fam. 5 valence e- -3 charge Group 16 Oxygen Fam 6 valence e- -2 charge Group 17 Halogens 7 valence e- -1 charge Group 18 Noble gases 8 valence e- 0 charge
Electron dot diagram Includes the symbol for the element surrounded by dots. Each dot stands for one valence electron.