Classifying the Elements Prentice-Hall Chapter 6.2 Dr. Yager

Objectives  Describe the information in the periodic table  Classify elements based on electron configuration  Distinguish representative elements and transition elements

What’s On the Periodic Table

Colors Distinguish Groups The Group 1A elements are called alkali metals. The Group 2A elements are called alkaline earth metals. The Group 7A elements are called halogens.

Physical Properties of Alkali Metals

Electron Configuration Elements can be sorted into noble gases, representative elements, transition metals, or inner transition metals based on their electron configurations.

Noble Gas The noble gases are the elements in Group 8A of the periodic table. The electron configurations for the first four noble gases in Group 8A are listed below.

The Representative Elements Elements in groups 1A through 7A are often referred to as representative elements because they display a wide range of physical and chemical properties. The s and p sublevels of the highest occupied energy level are not filled.The s and p sublevels of the highest occupied energy level are not filled. The group number equals the number of electrons in the highest occupied.. energy level.The group number equals the number of electrons in the highest occupied.. energy level.

Group 1A There is only one electron in the highest occupied energy level.

Group 4A There are four electrons in the highest occupied energy level.

Representative Elements Magnesium is used by chlorophyll in plants to convert sunlight into chemical energy.

There are two types of transition elements:  Transition metals  Inner transition metals They are classified based on their electron configurations. Transition Elements

In atoms of a transition metal, the highest occupied s sublevel and a nearby d sublevel contain electrons. In atoms of an inner transition metal, the highest occupied s sublevel and a nearby f sublevel generally contain electrons.

Blocks of Elements

Hydrogen   Hydrogen is the most common element in the universe. It is estimated that three out of every four atoms in the universe are hydrogen.   Because it consists of just one proton and one electron, hydrogen behaves unlike any other element.   Hydrogen is in a class by itself in the periodic table.   With its one electron, hydrogen can react with many other elements, including oxygen.

1. Which of the following information about elements is usually NOT included in a periodic table? a)color b)symbol c)atomic number d)atomic mass

1. Which of the following information about elements is usually NOT included in a periodic table? a)color b)symbol c)atomic number d)atomic mass

2. An alkali metal would have in the highest occupied energy level a)an s 2 electron b)an s 1 electron c)p 2 electrons d)p 6 electrons

2. An alkali metal would have in the highest occupied energy level a)an s 2 electron b)an s 1 electron c)p 2 electrons d)p 6 electrons

3. Which one of the following is incorrectly labeled? a)Ne, noble gas b)Cu, transition metal c)Ga, transition metal d)Cl, halogen

3. Which one of the following is incorrectly labeled? a)Ne, noble gas b)Cu, transition metal c)Ga, transition metal d)Cl, halogen

4. Transition metals are characterized as being different than representative elements because they have electrons in which orbitals? a) p b) d c) s d) f

4. Transition metals are characterized as being different than representative elements because they have electrons in which orbitals? a) p b) d c) s d) f