Group 4 element

Group	4
Period
4	22 Ti
5	40 Zr
6	72 Hf
7	104 Rf

In modern IUPAC nomenclature, Group 4 of the periodic table contains the following chemical elements:

• titanium (Ti)
• zirconium (Zr)
• hafnium (Hf)
• rutherfordium (Rf).

This group lies in the d-block of the periodic table. The group itself has not acquired a trivial name; it belongs to the broader grouping of the transition metals.

These elements are hard refractory metals. Titanium's mechanical properties make it useful in alloys. All isotopes of rutherfordium are radioactive, and have been synthesized in the laboratory, none of them have been found occurring in nature.

Biological occurances

The group 4 elements are not known to be involved in the biological chemistry of any living systems. They are hard refractory metals with low acqueous solubility and low availability to the biosphere. Titanium is one of the few first row d-block transition metals with no known biological role. Rutherfordium's radioactivity would make it toxic to living cells.

Explanation of right-hand periodic table slice:	Transition metals	atomic number in black are solids
		solid borders are older than the Earth (Primordial elements)	dotted borders are made artificially (Synthetic elements)

Template:WikiDoc Sources