Periodic Table
Stephanie Lursen
Alkali Metals:
Location
Characteristics
Example
Alkaline (Rare) Earth Metals:
Location
The alkaline earth elements are metallic elements found in the second group of the periodic table. All alkaline earth elements have an oxidation number of +2, making them very reactive. Because of their reactivity, the alkaline metals are not found free in nature. The Alkaline Earth Metals are: Beryllium, Magnesium, Calcium, Strontium, Barium, and Radium. In the picture (see above), the alkaline elements are orange.
Characterisitics
- An oxidation number of +2 which makes them very reactive
- Not found freely in nature
- Present in the earth's crust but not in their basic form
- Distributed in rock structure
- Two electrons in their outer shell
- High boiling points
- High melting points
- Low density
- Low electron affinity
- Low electronegativity
- Silver in color
- Ductile
- Malleable
- React easily with the halogens and water
- Softer and stronger than most other metals (except the alkali metals)
Example
Halogens:
Location
Characteristics
A unique characteristic of halogens is that they are the only element group that includes elements that belong to all three classical states of matter: solid, liquid, and gas at room temperature. The halogens, as a group, are extremely reactive. In their elemental form, they are found as diatomic molecules.
Example
Noble Gases:
Location
Characteritics
Example
Metals:
Location
Characteristics
- Shiny 'metallic' appearance
- Solids at room temperature (except mercury)
- High melting points
- High densities
- Large atomic radii
- Low ionization energies
- Low electronegativities
- Usually, high deformation
- Malleable
- Ductile
- Thermal conductors
- Electrical conductors
Example
Metalloids:
Location
Metalloids are the elements found between the boundary that distinguishes metals from non-metals. Metalloids have properties of both metals and non-metals. Some of the metalloids, such as silicon and germanium, are semi-conductors. It is shown in the picture above in the light blue section.
Characteristics
Example
Nonmetals:
Location
Characteristics
- High ionization energies
- High electronegativities
- Poor thermal conductors
- Poor electrical conductors
- Brittle solids
- Little or no metallic luster
- Gain electrons easily
Example
Transition Metals:
Location
Characteristics
- they are good conductors of heat and electricity
- they can be hammered or bent into shape easily
- they are less reactive than alkali metals such as sodium
- they have high melting points - but mercury is a liquid at room temperature
- they are usually hard and tough
- they have high densities
Example
Lanthanides:
Location
Characteristics
- Silvery-white metals that tarnish when exposed to air, forming their oxides.
- Relatively soft metals. Hardness increases somewhat with higher atomic number.
- Moving from left to right across the period (increasing atomic number), the radius of each lanthanide 3+ ion steadily decreases. This is referred to as 'lanthanide contraction'.
- High melting points and boiling points.
- Very reactive.
- React with water to liberate hydrogen (H2), slowly in cold/quickly upon heating. Lanthanides commonly bind to water.
- React with H+ (dilute acid) to release H2 (rapidly at room temperature).
- React in an exothermic reaction with H2.
- Burn easily in air.
- They are strong reducing agents.
- Their compounds are generally ionic.
- At elevated temperatures, many rare earths ignite and burn vigorously.
- Most rare earth compounds are strongly paramagnetic.
- Many rare earth compounds fluoresce strongly under ultraviolet light.
- Lanthanide ions tend to be pale colors, resulting from weak, narrow, forbidden f xf optical transitions.
- The magnetic moments of the lanthanide and iron ions oppose each other.
- The lanthanides react readily with most nonmetals and form binaries on heating with most nonmetals.
- The coordination numbers of lanthanides are high (greater than 6; usually 8 or 9 or as high as 12).
Example
Actinides:
Location
Characteristics
- All are radioactive.
- Actinides are highly electropositive.
- The metals tarnish readily in air.
- Actinides are very dense metals with distinctive structures. Numerous allotropes may be formed (plutonium has at least 6 allotropes!).
- They react with boiling water or dilute acid to release hydrogen gas.
- Actinides combine directly with most nonmetals.