More to Know about the Periodic Table! You know you love notes

REVIEW: Periods are horizontal (across) rows of elements on the periodic table. A row is called a period because the properties in a row follow a repeating, or periodic pattern as you move across each period. Periods are numbered 1-7. Groups or Families are vertical (up and down) columns and are called families because they share similar characteristics similar to our families.

All in the Family… Group 1:Alkali Metals Group 2:Alkaline Earth Metals Groups 3-12: Transition Metals Group 13: Boron Group Group 14: Carbon Group Group 15: Nitrogen Group Group 16: Oxygen Group Group 17: Halogens Group 18: Noble Gases

Electron Cloud Configuration – Energy Levels Although all the electrons in an atom are somewhere in the electron cloud, some electrons are closer to the nucleus than others. The different areas for an electron in an atom are called energy levels.

The closer an energy level is from the nucleus, the fewer electrons it can hold. The farther an energy level is from the nucleus, the more electrons it can hold. Electron locations generally start from the inner most energy level and work outward. E.C.C. – Distance

1 st energy level (closest to the nucleus) = up to 2 Es – Period 1 elements have 1 energy level 2 nd energy level = up to 8 Es – Period 2 elements have 2 energy levels 3 rd energy level = up to 18 Es; HOWEVER, we will consider 8 Es to be FULL – Period 3 elements have 3 energy levels 4 th energy level = up to 32 Es; HOWEVER, we will consider 8 Es to be FULL – Period 4 elements have 4 energy levels SKIP TRANSITION METALS (groups 3-12) E.C.C. – Quantity

Starting at the 3 rd energy level, electron configurations change slightly due to the characteristics of transition metals Since this is introductory chemistry, we will not explore the electron configurations of transition metals or of elements beyond period 4. E.C.C. – EXCEPTIONS

Farther an electron is away from nucleus: – more energy available – easier to remove Closer an electron is to nucleus: – less energy available – harder to remove E.C.C. – amounts of energy The energy level also relates to the amount of energy electrons have within the atom.

Electrons farthest from the nucleus have the highest amount of energy and are the easiest to remove. Electrons closest to the nucleus have the lowest amount of energy and are more difficult to remove because the closer a negatively charged electron is to the positively charged nucleus, the more strongly it is attracted to the nucleus Thus, removing electrons closest to the nucleus takes more energy than removing those that are farther away E.C.C. – amounts of energy

Valence Electrons The electrons in the outermost energy level of an atom are called valence electrons. The valence electrons determine whether an atom will form bonds. An atoms with a full outer energy level will not usually form bonds For example, the noble gases in group 18 are happy and therefore do not usually form bonds.

Valence Electrons The group number for of groups 1 and 2 indicate the amount of valence electrons The group number minus 10 for groups indicates the number of valence electrons. How many valence electrons?

Valence Electrons How many valence electrons? What Group?

Valence Electrons How many valence electrons? What Group?

Quote of the Day: “Equipped with his five senses, man explores the universe around him and calls the adventure Science.” ~ Edwin Powell Hubble, The Nature of Science, 1954 “