Malleable

Definition:

Can be hammered or rolled into flat sheets

Ductile

Definition:

Can be pulled out, or drawn, into long wires.

Diatomic Molecule

Definition:

Molecule made of two atoms.

Ex: O₂

Conductivity

Definition:

Transmission of heat or electricity through a substance.

Metals are good conductors of heat and electricity.

Period

Definition:

A horizontal row of elements in the periodic table.

Group

Definition:

Family or column.

Elements in the same vertical column have similar physical & chemical properties AND # of valence electrons.

Semiconductor

Definition:

Substance that can conduct electricity under some conditions but not under others.

Used in computer chips, transistors, lasers

"Metalloids"

Physical Properties of Nonmetals

"Low & Poor"

• dull
• brittle (not malleable)
• poor conductors of electricity and heat
• lower densities
• lower melting points
• not as strong
• not ductile

Physical Properties of Metals

"High & Good"

• shiny
• high melting points
• high density (heavy)
• very strong
• malleable
• ductile
• good conductors of heat and electricity

Chemical Properties of Metals

• Reactive
• Corrosive
• Metals give up their electrons

Chemical Properties of Nonmetals

• Nonmetals gain electrons or share electrons when reacting

Who created the Periodic Table?

Mendeleev

(Mendeleev and Myer are both credited)

What was the Periodic Table originally based on?

Increasing Atomic MASS (Mendeleev)

What are the two properties that the modern periodic table is based on?

Atomic NUMBER & electron configuration

(definitely know that it is by atomic number)

Why is the periodic table called the periodic table?

Elements have properties that occur periodically

Metalloids

• some properties of metals and some properties of nonmetals
• uses include semiconductors for computer chips and transistors
• all are solids at room temperature

Halogens

• Means "salt-forming"
• Contains 7 valence electrons
• Very reactive
• Considered dangerous (poisonous)

Alkali Metals

• Very reactive group
• Only 1 valence electron
• Group 1
• Not found free in nature; only in compounds

Alkaline Earth Metals

• Very reactive - not as reactive as group 1
• 2 valence electrons
• Group 2
• Found only in compound

Rare Earth Metals

• Includes the lanthanide & actinide series
• Two rows at the bottom of periodic table
• rare
• most man-made

Transition Metals

• Includes groups 3-12
• most are hard and shiny solids
• good conductors
• malleable

Noble Gases

• Inert gases
• Usually nonreactive because they are stable
• 8 valence electrons
• all are gases

Oxygen

• Oxygen Family
• Group 16
• Oxygen is a diatomic molecule (O₂)

Fluorine

• A halogen
• Most reactive element
• Oxidizing agent

Silicon

• Metalloid
• Used as a semiconductor

Carbon

• Nonmetal
• Carbon Family - Group 14
• Carbon is the only nonmetal in Group 14