First 20 Elements Of The Periodic Table: The atomic number and symbols are important in chemistry. The atomic number of elements gives us an idea about the atomic structure of elements ...

mass number = protons + neutrons. Name the first 20 elements. The first 20 elements of the periodic table are as follows: H – Hydrogen, He – Helium, Li – Lithium, Be – Beryllium ...

Physicists have filled in some longtime blank spaces on the periodic table, calculating electron affinities of the lanthanides, a series of 15 elements known as rare earths. Physicists at Michigan ...

Agrawal set an unofficial world record in April by writing out all 118 element ... on a blank periodic table in 91.65 seconds. That's almost exactly 2.5 characters per second. At first I was ...