Those in columns 1 and 2, and 13-18.
a.k.a. the "s" and "p" block elements
6
Now (2013) are considered as natural chemical elements 97 elements (including berkelium).
Today 94 elements (1 to 94) are considered natural chemical elements.
Today are known 118 chemical elements; 98 are considered as natural elements (but some have also and an artificial origin).
Because they have many similar chemical properties.
Now are known 118 chemical elements.
92 elements occur naturally on the periodic table.
75 dissolved chemical elements
Water is considered a pure chemical substance. Its mass and properties are similar to many of the other constituent elements.
Now (22.08.2012) 118 chemical elements are known.
False; practically all the chemical elements have many uses.
there are loads!