General chemistry

General chemistry

Contributors in General chemistry

General chemistry

A chemical element in the lanthanide series, with the symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination ...

thulium

Chemistry; General chemistry

A chemical element that has the symbol Tm and atomic number 69. Thulium is the second least abundant of the lanthanides (promethium is only found in trace quantities on Earth). It is an easily ...

lutetium

Chemistry; General chemistry

A chemical element with the symbol Lu and atomic number 71. It is the last element in the lanthanide series, which, along with lanthanide contraction, explains several important properties of ...

hafnium

Chemistry; General chemistry

A chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in zirconium minerals.

tantalum

Chemistry; General chemistry

A chemical element with the symbol Ta and atomic number 73. Previously known as tantalium, the name comes from Tantalus, a hero in Greek mythology. (3) Tantalum is a rare, hard, blue-gray, lustrous ...

tungsten

Chemistry; General chemistry

A chemical element with the chemical symbol W and atomic number 74. A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It ...

rhenium

Chemistry; General chemistry

A silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's ...