CHEMISTRY - PERIODIC TABLE - ACTINIDE #10

ACTINIDE

Actinide Series of Metals

There are two rows under the periodic table: the lanthanide and actinide series. 

• The lanthanide series can be found naturally on Earth. Only one element in the series is radioactive. 
• The actinide series is much different. They are all radioactiveand some are not found in nature. 

Some of the elements with higher atomic numbers have only been made in labs. There are special laboratories across the world that specialize in experimenting on elements. Some of these particle accelerators have pounded atomic particles into elements with lower atomic numbers. The buildup of additional parts creates short-lived, high atomic number elements. 

Meet the Family

The actinide family is comprised of fifteen elements that start with actinium (Ac) at atomic number 89 and finish up with lawrencium (Lr) at number 103.
You have probably heard of plutonium (Pu), since it was used in atomic bombs. Uranium (U) is also well known for its radioactivity. They aren't all used to blow up the world. Some of them help us out every day. You can find americium (Am) is some metal detectors. 

ACTIVITY - PERIODIC TABLE 

CHEMISTRY - PERIODIC TABLE - LANTHANIDE #9

LANTHANIDE

Lanthanide Series of Metals

When you look at the periodic table, you will see two rows that kind of sit off to the bottom. They are part of the whole table, but it is easier to print the table when they are on the bottom. One of those rows is called the lanthanide series. 
There are a bunch of names you may hear that describe these 15 elements. Some people say lanthanide, some say rare-earth metals, and some say inner-transition elements. No matter what you choose, everyone will know what you mean if you say lanthanide. 

Meet the Family

The lanthanide family is comprised of fifteen elements starting with lanthanum (La) at atomic number 57 and finishing up with lutetium (Lu) at number 71.
You might find some of these elements in superconductors, glass production, or lasers. 

CHEMISTRY - ELEMENT OF THE DAY - SILICON

14

Si

Silicon

28.0855

Atomic Number: 14

Atomic Weight: 28.0855

Phase at Room Temperature: Solid

Element Classification: Semi-metal

Period Number: 3    Group Number: 14    

Group Name: none

What's in a name? From the Latin word for flint, silex.

Say what? Silicon is pronounced as SIL-ee-ken.

History and Uses:

Silicon was discovered by Jöns Jacob Berzelius, a Swedish chemist, in 1824 by heating chips of potassium in a silica container and then carefully washing away the residual by-products. Silicon is the seventh most abundant element in the universe and the second most abundant element in the earth's crust. Today, silicon is produced by heating sand (SiO₂) with carbon to temperatures approaching 2200°C.

Two allotropes of silicon exist at room temperature: amorphous and crystalline. Amorphous appears as a brown powder while crystalline silicon has a metallic luster and a grayish color. Single crystals of crystalline silicon can be grown with a process known as the Czochralski process. These crystals, when doped with elements such as boron, gallium, germanium, phosphorus orarsenic, are used in the manufacture of solid-state electronic devices, such as transistors, solar cells, rectifiers and microchips.

Silicon dioxide (SiO₂), silicon's most common compound, is the most abundant compound in the earth's crust. It commonly takes the form of ordinary sand, but also exists as quartz, rock crystal, amethyst, agate, flint, jasper and opal. Silicon dioxide is extensively used in the manufacture of glass and bricks. Silica gel, a colloidal form of silicon dioxide, easily absorbs moisture and is used as a desiccant.

Silicon forms other useful compounds. Silicon carbide (SiC) is nearly as hard as diamond and is used as an abrasive. Sodium silicate (Na₂SiO₃), also known as water glass, is used in the production of soaps, adhesives and as an egg preservative. Silicon tetrachloride (SiCl₄) is used to create smoke screens. Silicon is also an important ingredient in silicone, a class of material that is used for such things as lubricants, polishing agents, electrical insulators and medical implants.