Chromium
Into the world of CHROMIUM
Information
History
The element chromium was discovered in 1797 by Louis-Nicholas Vauquelin. He made his discovery when he mixed Crocoite and Hydrochloric acid.
Properties
Chromium is a very hard and brittle metal. Its color is a bluish silver. The metal Chromium is also very corrosion resistant.
Uses
Can be polished to a shiny surface. Often used as a surface for cars.
Used to make brick molds because of chromium's high melting point.
Added to other metals to harden them.
Compounds
Lead Chromate- (PbCro4) Yellow pigment in paint.
Chomic Oxide- (Cr2O3) Green pigment in paint.
Potassium dichromate- (K2Cr2O7) Used in the tanning of leather.
Periodic Table
Atomic Number and Mass
The atomic number for Chromium is 24.
The Atomic mass of Chromium is 51.9961.
Number of each Particle
24 Protons
28 Neutrons
24 Electrons
Notation
Nuclide Notation- 51.99
24 Cr
Hyphen Notation- Cr- 51.99
Model
Valence Electrons
1 Valence electron
Lewis Dot
- Cr
Group
Group Name
Transition Metals
Group Properties
- Good conductors of heat and electricity
- Malleable
- Less reactive than alkali metals
- High melting points- 3,465 F
- High densities
- Usually high and tough
Reaction Type
Chromium Oxide
Synthesis Reaction
(2Cr+3O yields Cr2+ O3)
Mole Ratios : 2 Mol Cr : 3 Mol O 2 Mol Cr: 1 Mol Cr2O3
Bonding
Chemical Formula
Chromium oxide's formula is CrO
Bonding Type
Ionic Bonding
Percent of Each Element
67% Chromium
33% Oxygen
Creativity
Acrostic Poem
Chrome
High density
"mirRor like reflection" when polished
Opaque
used to Make stainless steel
relatIvely hard
U
alMost never found in its elemental state in nature