1. C3H8 + 3O2 > 3CO2 + 4H20

2. Al2 (5O3)3 + NaOH > Na25O3 + 2A1(OH)3

3. 4aI2O3 + 9Fe > FE 304 + 8al

4. 2kc1O3 > 2kc1 + 3O2

5. 3c4 + 8hno3 >  3c4 (no3)2 + 2no + 4h20

In physics, a conservation law states that a particular measurable property of an isolated physical system does not change as the system evolves over time. Exact conservation laws include conservation of energy, conservation of linear momentum, conservation of angular momentum, and conservation of electric charge. There are also many approximate conservation laws, which apply to such quantities as mass, parity, lepton number, baryon number, strangeness, hypercharge, etc. These quantities are conserved in certain classes of physics processes, but not in all.

In 1869 Russian chemist Dimitri Mendeleev started the development of the periodic table, arranging chemical elements by atomic mass. He predicted the discovery of other elements, and left spaces open in his periodic table for them.The Russian chemist Dmitri Mendeleev was the first scientist to make a periodic table similar to the one used today. Mendeleev arranged the elements by atomic mass, corresponding to relative molar mass. In 1940 Edwin McMillan and Philip H. Abelson identify neptunium, the lightest and first synthesized transuranium element, found in the products of uranium fission. Also in 1898 Marie and Pierre Curie isolated radium and polonium from pitchblende