6.1 The Periodic Table

Mendeleev’s Periodic Table

• Set up by atomic mass v. atomic number-modern

Numbering the Periodic Table

• Groups: vertical

–Similar properties in each

• Periods: horizontal–No similar properties

–Increasing atomic number

Mapping the Periodic Table:Metals, Nonmetals, Metalloids

Definitions

● Metal: good conductor of heat and electricity, high luster (sheen), ductile, malleable○ With the exception of mercury (Hg), all metals are solid

at RT● Nonmetal: Most are gases at RT (Sulfur and phosphorous

are solids, bromine is a liquid)○ Generally poor conductors of heat and electricity○ solids tend to be brittle

● Semi-metal (metalloid): has a mix of properties of metals and nonmetals]○ Ex: pure silicon is a poor conductor of electricity, but

when mixed with boron, it becomes a good conductor of electric current

Group Names, Representative, Transition metals and Inner transition

(rare earth) metals

1. Name the 3 broad classes of elements2. Which of these sets of elements have similar physical and

chemical properties?1. oxygen, nitrogen, carbon, boron2. strontium, magnesium, calcium, beryllium3. nitrogen, neon, nickel, niobium

3. Identify each as a metal, nonmetal, or semi-metal1. gold2. sulfur3. silicon4. barium

4. Name 2 elements that have similar properties to sodium

Ch. 6.2 and 6.3Electron configuration

Ions and charges

Periodic Trends

Electron config. Blocks

Valence electrons

• Valence Electrons (v.e.): – electrons used in bonding elements– Electrons in the highest energy level

• s and p sublevels – maximum is 8

– Valence electrons is the same as the group number (for representative elements)

• Example: Mg is group 2A, has 2 v.e.

Valence electrons in P.T.

Lewis Dot Structures

Ions

• Atoms gain or lose electrons to obtain a noble gas configuration– Cations: positive charge bc they LOSE

electrons.• Ca: loses 2 e- becomes +2 charge to be like Ar

(Ca2+)

– Anions: negative charge bc they GAIN electrons

• Cl: gains 1 e- become 1- charge to be like Ar (Cl-)

Charges of the Ions

• Atomic Size (radius): one half the distance between the nuclei of 2 atoms of the same element when 2 atoms are joined.– Ions: atom (or group of atoms) that has a

positive or negative charge by losing or gaining electrons.

• Anions: larger than original atom• Cations: smaller than original atom

Atomic Radius

Vocabulary

• Ionization Energy: energy required to remove the first electron from an atom. 

• Electronegativity: the ability of an atom to attract an electron when an atom is in a compound. (number value assigned arbitrarily 0.7- 4)

Increasing electronegativity and ionization energy