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History of the Periodic Table 1869 - Mendeleev published a
classification scheme of all the currently known elements
Organized elements based on similar characteristics.
Left blank spaces in table for undiscovered elements.
Mendeleev’s Periodic Table (1869)Mendeleev arranged the elements on his table in order of increasing atomic mass.
The Periodic Law
In the modern periodic table, elements are arranged in order of increasing atomic number
Periodic Law – when elements are arranged in order of increasing atomic number, there is a trend in their physical and chemical properties
Metals, Metalloids and Nonmetals
Elements can be grouped into three broad classes based on their general properties
MetalsNonmetalsMetalloids
Metals: Generally solid at room temp. Ductile – drawn into wires. Malleable – hammered into sheets Shiny surface Conduct heat and electricity
• Nonmetals: • Varying properties, but are generally
poor conductors of heat and electricity
• Brittle
Practice
Tell me all you can about the following elements:
1. Titanium (Ti)2. Germanium (Ge)3. Calcium (Ca)4. Fluorine (F)
Section 6.2 - Classifying the Elements
The periodic table displays the symbols and names of the elements, along with information about the structure of their atoms (# of protons, neutrons, and electrons)
Electron Configurations in Groups Elements can be sorted into 4 different
groupings based on their electron configurations:
1) Noble gases
2) Representative elements
3) Transition metals
4) Inner transition metals
Electron Configurations in Groups
1) Noble gases elements in Group 8A
2) Very stable = do not react• Noble gases have an electron
configuration that has the outer s and p sublevels completely full
Electron Configurations in Groups2) Representative Elements
are in Groups 1A through 7A• Display wide range of
properties, thus a good “representative”
• Include metals, nonmetals, metalloids, solids, gases, or liquids
• Their outer s and p electron configurations are NOT filled
Electron Configurations in Groups
3) Transition metals are in the “B” columns of the periodic table
• Electron configuration has outer s sublevel full
• Elements in the “d” sublevel• A “transition” between the metal area and
the nonmetal area
Electron Configurations in Groups
4) Inner Transition Metals are located below the main body of the table, in two horizontal rows
• Electron configuration has the outer s sublevel full
• Elements in the f sublevel
1A
2A 3A 4A 5A 6A 7A
8A Elements in the 1A-7A groups
are called the representative elements
outer s or p filling
The group B are called the transition elements
These are called the inner transition elements, and they belong here
Groups of elements - family names Group 1A – alkali metals
Forms a “base” (or alkali) when reacting with water Exception is Hydrogen
Group 2A – alkaline earth metalsAlso form bases with water; do not
dissolve well, hence “earth metals” Group 7A – halogens
Means “salt-forming”
Groups of the periodic table: Representative Elements Noble Gases Transition Metals Inner Transition Metals
Family names: Alkali metals Alkaline earth metals Halogens
The Groups of the Periodic Table
Practice
Tell me all you can about the following elements:
1. Titanium (Ti)2. Germanium (Ge)3. Calcium (Ca)4. Fluorine (F)
Section 6.3 – Periodic Trends
Properties of elements are related to their location on the periodic table
We will be studying 3 periodic trends:–Atomic Radius–Ionization Energy–Electronegativity
1. Atomic Radius or Atomic Size
One-half the distance from center to center of two atoms
Atomic Radius
Atomic Radius or Atomic SizeWhat do you notice about the atomic radii of the elements on the periodic table?
Atomic Radius increases towards the bottom left corner of the PT
Which element has a greater atomic radius? F or Cs Ga or K Kr or Rb Ba or Si Fr or W O or Ag
Atomic Radius/Size Practice
Ions
When elements combine in compounds, they transfer electrons.
Ions are atoms that have a positive or negative charge.
Normally, atoms are neutral because they have the same number of protons and electrons
Ionic SizeCations are always
smaller than the atoms from which they form
Anions are always larger than the atoms from which they form
• Does this make sense?• Where are electrons located in the
atom?• Around the nucleus
• The more electrons around the nucleus, the larger the atom will be.
Practice
Which of the following is larger? Na or Na+
Al or Al3+
I or I-
Ca2+ or Ca S or S2-
O2- or O
Ionization Energy What trend do you notice about the ionization
energy of the elements on the periodic table?
Ionization Energy increases towards the top right corner of the PT
• Does this make sense?• Which elements are the most
stable?• Elements with full orbitals
• The more stablethe elements is, the harder it will be to remove an electron.
Which of these elements has a greater ionization energy? Kr or Ar Al or Na S or Rb Si or Cs He or Ca P or O
Ionization Energy Practice
ElectronegativityWhat trend do you notice about the electronegativity of
the elements on the periodic table?
Electronegativity increases towards the top right corner of the PT
• Does this make sense?• Which elements want electrons?
• Elements closest to filling their orbitals
• The closer the elements is to filling its orbital, the more it will attract electrons.
Which element has greater electronegativity? Na or F Ca or C Al or Mg Sr or Al Ca or K Cl or F
Electronegativity Practice