Chapter 6 Periodic table 6.2: Modern Periodic Table

3) Sorting elements based on general properties

A. Classification of elements

B. Noble gases, representative elements and transition elements (transition and inner-transition metals)

Chemistry _ NotesDr. Chirie Sumanasekera

11/3/ 2017

3) Key Points on the arrangement of Elements:A. Classification of elements:

Elements are classified based on properties. Each square in the periodic table gives us specific information about each element.

Information about elements found in periodic table:

1. Symbols and name of elements

2. Atomic structure (number of protons, neutrons and electrons)

3. Physical state at Room Temperature (RT)

4. Electron configuration

5. Some Chemical and physical properties (Metals, non metals and metalloids, noble gasses, halogens, alkali metals, alkaline earth metals…)

B) Noble gases, representative elements and transition elements (transition and inner-transition metals)

Group 1(1A) = Alkali metals

Group 2(2A) = Alkaline earth metals

Alkali metals:

1. Very soft (can be cut with a knife)

2. Very reactive

3. Low melting and boiling point

4. One electron in last energy level. Readily loses this electron and becomes a 1+ cation (very electro-negative)

Alkaline earth metals:

1. Shiny/ silvery white

2. Somewhat reactive

3. Low melting and boiling point

4. Two electrons in last energy level. Readily loses these two electrons and becomes a 2+ cation (electro-negative)

Li and Na are so reactive. They are stored in oil to prevent the reaction with oxygen

Group17(7A) = Halogens

Group 18 (8A) = Noble gases

Halogens:

1. All can form Di-atomic gases (Cl2, F2, Br2…)

2. AT RT, Cl and F are gases, Br is a liquid and I is a solid.

3. Some have odor and color

4. Seven electrons in energy highest energy level. Readily gains an electron from a donor-atom and becomes a 1- anion (very electro-positive)

Noble gases:

1. All are mono-atomic gases at RT

2. Odorless and colorless

3. Very non-reactive

4. Eg. He, Ne, Ar, Kr, Xe, Rn

5. Highest energy level is fully occupied by electrons

Cl Br I

B) Noble gases, representative elements and transition elements (transition and inner-transition metals)

Transition elements (Groups 3-12 or B-group) (two types: transition metals and inner transition metals)

Transitional metals:

Highest occupied sub-level is d.

Inner T. metals:

Highest occupied sub-level is f

B) Noble gases, representative elements and transition elements (transition and inner-transition metals)

3) Key Points on the arrangement of Elements:A. Classification of elements based on electron configuration in groups:

1. Noble gases (inert gases, have 8 electrons in highest occupied sub-levels) and Halogens

2. Representative elements (display a wide range of physical and chemical properties)

3. Transitional elements (elements in the B-groups, highest occupied sub-level is a d-orbital)