Top 50 Science GK Questions and Answers

The quantitative relationship between reactants and products is called stoichiometry. The term stoichiometry is derived from two Greek words: stoichion (meaning "element") and metron (meaning "measurement").

The Greeks called these particles atoms, meaning indivisible, and the modern word "atom" is derived from this word. Democritus proposed that different types and combinations of these particles were responsible for different forms of matter.

In 1793, John Dalton went to Manchester to teach mathematics, physics and chemistry in a college. There he spent most of his life in teaching and research. In 1808, he presented his atomic theory, which proved to be an important theory for the study of substances.

An object which completely absorbs radiation of all wavelengths incident on its surface is called a black body. Black bodies absorb radiation in a particular and continuous spectrum and re-emit it when heated.

Saturated hydrocarbons burn with a blue flame and unsaturated hydrocarbons burn with a yellow sooty flame.

Many orbitals are possible in an atom. Qualitatively, these orbitals can be differentiated on the basis of their size, shape and orientation. Smaller orbitals mean that the probability of finding the electron closer to the nucleus is greater. Similarly, shape and orientation indicate that the probability of finding an electron is greater in one direction than in another. Atomic orbitals can be distinguished by quantum numbers. Each orbital is represented by three quantum numbers n, ℓ and m.

A nodal surface, also called a radial node, is a hollow spherical region that cannot contain electrons. A nodal plane is also called an angular node, which is either a plane where electrons cannot occur, or a conical surface (d z 2 orbital).

For this theory and its applications which particularly resulted in the discovery of allotropic forms of hydrogen, Heisenberg was awarded the Nobel Prize for Physics for 1932. His new theory was based only on what could be observed, that is, on the radiation emitted by the atom.

At the end of the war, Heisenberg was captured by the Allies and imprisoned in England for six months. He was released and returned to Germany where he re-founded the Kaiser Wilhelm Institute for Physics, but renamed it the Max Planck Institute in honor of his friend and colleague.

The Karlsruhe Congress was called so that European chemists could discuss matters of chemical nomenclature, notation, and atomic weights. The organization, invitation and sponsorship of the conference was handled by August Kekulé, Adolf Wurtz and Carl Weltzien.