Ch 6 Notes

The Periodic Table -

• elements are arranged in groups based on properties

• Dmitri Mendeleev arranged the elements according to atomic mass and used the arrangements to predict the properties of missing elements.

• The modern periodic table is arranged in order of increasing atomic number.

• The atomic number is the total number of protons in the nucleus.

• The electron mostly determines the properties of an element.

• Indium: ______ protons ______ electrons

• 49 49

• Groups -

• Vertical

• Columns

• Periods – Horizontal Rows

• Magnesium is in the same group as calcium.

Magnesium is in the same period as phosphorus.

Three classes of elements are metals, nonmetals, and

metalloids.

• Metals include the majority of the elements.

Pt is a metal. Si is a metalloid. Kr is a nonmetal.

Metals are shiny, malleable (hammered into sheets), ductile (drawn into wires),

solid at room temperature, and good conductors of electricity.

Nonmetals are poor conductors of electricity, often gases at room temperature, and brittle if

solid.

Metalloids have some properties of metals and nonmetals.

Antimony

Boron

Arsenic

Germanium

Group 1A - alkali metals

Group 2A - alkaline earth metals

Group 7A - halogens

Group 8A - noble gases

Groups 1A through 7A - representative elements

Group B - transition metals

Aluminum is a representative element.

Copper is a transition metal.

Na is an _______________________

• alkali metal

Mg is an _______________________

• alkaline earth metal

F is a ________________________

• halogen

Ne is a ______________________

• noble gas

Ag is a ______________________

• transition metal

There are 5 electrons in the valence level of an element in

Group 5A.

N, P, As, and Sb have the same number of electrons in their

valence levels.

The electron configuration for an element in the halogen group should always end with ns2np5. The electron configuration of the

element chlorine ends in 3s23p5.

Noble gases (inert gases) have their highest occupied s and p

sublevels filled.

Fe contains an electron in a d sublevel.