The Periodic Table and Periodic Law Objectives: AHSGE Reading 4.3 Discern organizational patterns. Other AOD C.3.2 Recognize periodic trends of elements,

The Periodic Table and Periodic Law

Objectives:AHSGE Reading 4.3 Discern organizational

patterns.

Other AOD C.3.2 Recognize periodic trends of elements, including the number of valence

electrons, atomic size, and reactivity.

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Periodic Law• Dmitri Mendeleev’s periodic table had the

elements arranged in order of increasing mass.

• How is the modern periodic table arranged differently?

• Def: There is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number

The Modern Periodic Table• What are columns called?

Answer: Groups

• What are horizontal rows called?

Answer: Periods

• Label groups and rows on your blank periodic table as instructed, or as they are labeled on pp.156-157 of your textbook, if you are absent.

The Modern Periodic Table (continued)

• Representative elements: elements in the A groups (1A-8A) – AKA, “the main group”– Possess a wide range of physical and

chemical properties

• Transition elements: elements in the B groups (1B-8B)

• A more recent numbering system (1-18) is shown in your book., but what is an advantage to using the older system?

Metals• Describe some properties of metals.

• Metals: – Generally shiny–Most are solid at room temperature– Good conductors of heat and electricity– Ductile and malleable

• Most group A and all group B elements are metals.

Metals (continued)• Groups 1A and 2A, EXCEPT HYROGEN, are

metals.• If H is so different, why is it in groups 1A?

What does it have in common with the other elements in that group? (Hint: last test)

• The other elements in group 1A are called alkali metals.

• Group 2A elements are alkaline earth metals.

Metals (continued)• Both groups 1A and 2A are highly

reactive (1A more so).

• Why would group 1A be more reactive than group 2A?

Answer: Group 2A has a FILLED s orbital, but group 1A’s s orbital is only half-filled, so that electron is still looking for a partner to hook up with.

Metals (continued)• Group B elements:– Transition metals: located on the main body

of the periodic table– Inner transition metals: the 2 rows located

along the bottom of the periodic table

Nonmetals• Describe some properties of nonmetals.

• Nonmetals:– Generally gases or brittle, dull-looking solids– Poor conductors of heat or electricity– The ONLY nonmetal that is a liquid at room

temperature is bromine.

• Located in the upper right portion of the periodic table

Nonmetals (continued)• Halogens: Group 7A elements; highly

reactive

• Noble gases: Group 8A; extremely Unreactive.

• Why are group 8A elements unreactive?

Answer: Their outer valence shell is filled, so they have no need to pair up with anyone else.

Metalloids• Have properties of both metals and

nonmetals.

• Stair-step down from boron to astatine and germanium to polonium.

• They separate the metals and nonmetals on the periodic table.

Assignments 1. Color-code the metals, nonmetals, and

metalloids on your blank periodic table.

2. Complete Study Guide for Content Mastery, p.32 (18-29)