Mendeleev was ………… chemist.
a) Italian
b) Russian
c) English
d) none of these
The development of periodic table started in
a) 1800
b) 1976
c) 1874
d) 1864
Initially elements were divided in… classes.
a) three
b) two
c) four
d) six
Explanation:Initially elements were divided in two classes metals & non metals.
Elements were divided into ……….
a) metals
b) non metals
c) a & b both
d) metalloid
In ……….. J.W.Dobereiner classified chemically similar elements in groups of three.
a) 1827
b) 1917
c) 1817
d) 1927
Explanation:Johann Wolfgang Döbereiner was a German chemist
who is best known for work that foreshadowed the periodic law for the chemical
elements, and for inventing the first lighter, which was known as the
Döbereiner's lamp. He became a professor of chemistry and pharmacy at the
University of Jena.
….……classified elements into triads.
a) Mendeleev
b) J.W.Dobereiner
c) Lavoisier
d) Newlands
