organization of the periodic table classifying the elements
TRANSCRIPT
Organization of the Periodic Table
Classifying the Elements
Dmitrii Mendeleev
• Organized his periodic table by the elements increasing atomic mass
Modern Periodic Table
• The modern periodic table is organized by increasing atomic number
Periodic Law• The Periodic Law states that
when elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.
Periods
• The horizontal rows• 1 – 7 periods• The atomic number increases
across a period from left to right
Groups• The vertical columns of the periodic table (1-18)
• All elements in a group have the same number of valence electrons
• All the elements in a group have very similar chemical and physical properties
Elements can be classified as metals,
non-metals or metalloids
Metals• Good conductors of heat and
electricity• High luster (shiny)• Malleable and ductile• Solid at room temperature (except
for Mercury)• Most elements are metals – 80%
Non-metals• Poor conductors of heat and
electricity
• Vary in properties, many are gases, some are solids and liquid
• Solid forms are dull and brittle
Metalloids• Share properties of both metals and
nonmetals
• A metalloid may behave as a metal under some conditions, but the same metalloid may behave as a nonmetal under other conditions
• Ex: May be a good conductor but brittle
Metals (left side) Non-metals (right side) Metalloids (staircase)
Metals = GreenNon-metals = BlueMetalloids = Pink
Label the following elements as a metal, non-metal, or metalloid
C = carbon Non-metal
Mg = magnesium metal
Bi = bismuth metal
Si = silicon metalloid
The periodic table consists of Representative Elements
and Transition Elements (Transition Metals and Inner
Transition Metals)
Representative Elements • Found in groups 1 - 2 and groups 13 – 18 • Wide variety of properties that represent the
table as a whole • Represent each category of metals,
nonmetals, and metalloids• Represent each state of matter solids, liquids
and gasses 13 14 15 16 173A 4A 5A 6A 7A
1A 22A
Transition metals
• Groups 3 - 12 (middle of the periodic table)• These metals are solid at room temperature
(except for Mercury)
Inner transition metals
• Found underneath the periodic table• Lanthanide series - period 6 • Actinide series - period 7 • These metals are solid at room temperature
Inner Transition Metals
Representative Elements: yellow Nobel Gasses: purpleTransition Metals: orangeInner Transition Metals: green
Important Groups
• There are groups of elements in the periodic table that are given special names
• Elements in a group share similar chemical and physical properties
Alkali Metals • Li, Na, K, Rb, Cs, Fr • Group 1 (1A) – excluding
Hydrogen• 1 valence electron• Very unstable and highly
reactive• Extremely soft metals • All have low densities, melting
and boiling points.
Alkaline Earth Metals • Be, Mg, Ca, Sr,
Ba, Ra
• Group 2 (2A)
• 2 valence electrons
• Very reactive
• Bond and lose 2 electrons
Halogens• F, Cl, Br, I, At
• Group 17 (7A)
• 7 valence electrons
• Bond and gain 1 more electron to make their outer energy level full.
• A halogens bond with alkali metals to form a salt
Noble Gasses
• Most stable of the elements (non-reactive)• Outermost energy level or shell is full, so they
do not naturally bond with other elements• Share properties like high densities, high
melting points, colorless, odorless, and tasteless
• He, Ne, Ar, Kr, Xe, Rn • Group 18 (8A)• 8 valence electrons
Lanthanide Series • “Rare-Earth elements” • Found on the top row of the inner transition
metals • Named from element Lanthanum (La) atomic
number 57 - common properties
Actinide Series • Radioactive metals • Found on the bottom row of the inner
transition metals • Named after the element Actinium (Ac)
atomic number 89 - common properties