Periodic Table Notes How is the periodic table organized?
The modern periodic table was created by Russian chemist, Dmitri Mendeleev.
Elements on the periodic table arranged from left to right in order of increasing atomic number.
The most reactive elements are at the top left & the bottom right of the table.
Vertical columns are called groups (families)… numbered 1 -18.
Elements within a group have similar properties & contain the same number of valence electrons in their outer energy shell (level).
Valence electrons determine the element’s chemical properties.
Horizontal row of elements are called periods. Numbered 1 -7.
Elements of the same period pass from a strong metallic nature on the left to a strong nonmetallic nature to the right.
The period number tells how many energy levels the element has.
The element farthest to the right in a period is a noble gas with a full outer energy level.
METALS • Found to the left of the zig-zag on the periodic table. • 75% of all elements
METALS With the exception of Mercury, all metals are solid at room temperature. • Reactive elements… able to make alloys (combining 2 or more different metals). •
METALS • Most are good conductors of electricity & heat. • Shiny luster- ability of a substance to reflect light.
METALS • Some are ductile- can be drawn into wire. • Some are malleablecan be hammered into sheets without breaking.
Examples of metals on the periodic table… • Group 1 - Alkali Metals • Group 2 - Alkaline Earth Metals • Groups 3 -12 - Transition Metals
NONMETALS • Found to the right of the zig-zag on the periodic table. • May be solid, liquid or gas at room temperature.
NONMETALS • Reactive elements… gain electrons easily. • Poor conductors of electricity & heat.
NONMETALS • Dull luster- does not reflect much light. • Brittle as solids. (break easily)
**NON-METALS Many are essential for life, including Carbon, Sulfur, Nitrogen, Oxygen, Phosphorus & Iodine
Examples of nonmetals on the periodic table… • Group 17 Halogens • Group 18 - Noble gases
METALLOIDS • Share properties of both metals & nonmetals • Found along the zigzag on the periodic table.
Metalloids include: Boron, silicon, germanium, arsenic, antimony, tellurium, polonium & astatine.