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 elements
2. Which of these sets of elements have similar physical and
chemical properties?
1. oxygen, nitrogen, carbon, boron
2. strontium, magnesium, calcium, beryllium
3. nitrogen, neon, nickel, niobium
3. Identify each as a metal, nonmetal, or semi-metal
1. gold
2. sulfur
3. silicon
4. barium
4. Name 2 elements that have similar properties to sodium
Ch. 6.2 and 6.3
Electron 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