Periodic Table

METALLOIDS

All about metalloids

Metalloids are located along the stair-step line that distinguishes the metals and nonmetals in the periodic table. The metalloids are Boron (B), Silicon(Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te), and Astatine (At).

Metalloids are classified as “other metals.”

An everyday example of a metalloid is silicone. Silicone is used in computer chips, glass, and some bake-ware.

Metalloids discovery location and discoverer

Boron: Paris, France/

Joseph Louis Gay-Lussac andLouis Jacques Thénard


Silicon: Sweden/

Jöns Jacob Berzelius


Germanium: Germany/

Clemens Winkler


Arsenic: it's discovery was unrecorded/

Albertus Magnus


Antimony: Egypt/

Vannoccio Biringuccio


Tellurium: Transylvania/

Franz-Joseph Müller von Reichenstein


Astatine: USA/

Dale R. Corson, Kenneth Ross MacKenzie, Emilio Segrè


Date Found

Boron - 1808


Silicon- 1824


Germanium- 1886


Arsenic- 1250


Antimony- 300 BC


Tellurium- 1782


Astatine-1940



http://www.chemicalelements.com/elements/po.html

Melting and Boiling Point of all Metalloids

Boron:

-mp-2076 °C

-bp-2076 °C


Silicon:

mp-1414 °C

bp-3265 °C


Germanium:

mp-938.25 °C

bp-2833 °C


Arsenic

mp-817°C

bp- 613.0 °C


Antimony

mp-630.63 °C

bp-1587 °C


Tellurium

mp-449.51 °C

bp-988 °C


Astatine

mp-302 °C

bp-337 °C



http://www.ptable.com/

Number of Valence Electrons

Boron-3


Silicon-4


Germanium-4


Arsenic-5


Antimony- 5


Tellurium- 6


Astatine- 7



http://education.jlab.org/itselemental/ele014.html

Safety Concerns of Metalloids

-Soluble inorganic arsenic is toxic. Effects can include skin lesions, peripheral neuropathy, diabetes, cardiovascular diseases, and cancer.


-Breathing in levels of boron irritates the nose, throat, and eyes.


http://www.youtube.com/watch?v=2WDED5qaflE&edufilter=Db24N54Eu_vpe4P65Iz5FA&safe=active

PROJECT BY

Angela D'Amato, Claire Parker, Muskan, and Emma Morin