CSIR – UGS NET/JRF EXAM. SOLVED PAPERS

Chemical periodicity

Key points:

1) You know why they call it the periodic table?

  It's because the rows are called periods.

2) Dmitry Mendeleev, the creator of the table, was late in  submitting his work on all 63 elements.

3) There are 118 confirmed elements in the periodic table. Among those, 90 elements can be found in nature, others are strictly man-made. Technetium was the first man-made element

4) Hydrogen is the lightest element with its atomic weight 1 and that is why it can be found in the top left corner of the periodic table

5) Uranium is the heaviest element with an atomic weight of 238.

6) Helium, neon, argon, krypton, xenon, and radon are known as the Noble Gases as they were believed to be unreactive. But recent studies have shown reactive compounds are xenon, krypton and radon.

7) The International Union of Pure Applied Chemistry (IUPAC) is responsible for maintaining the periodic table

8) Most of the elements on the periodic table are metals-- almost 75 percentage.

9) Different forms of pure elements are called allotropes. For example, diamond, graphite, buckminsterfullerene, and amorphous carbon are allotropes of one pure element Carbon.

10) Mendeleev's periodic table was designed in the order of increasing atomic weight while the modern periodic table is designed according to increasing atomic number

11) The only two elements that are liquid in room temperature are mercury and bromine.

Four new elements has recently discovered in 2016.

The names of  the elements 113, 115,117 & 118 are Nihonium (Nh), Moscovium (Mc), Tennessine (Ts)  & Oganesson (Og).

The element “Nh” were named from the place of Japan “Nihon” means the land of rising sun in Japanese.

The elements “Mc” & “Ts” were named from their geographical regions. 

While the element “Og” was named in the honour  of Russian nuclear physicist “Yuri Oganessian”.