What is mean by periodic table of element and it's connection with radioactivity?

Answer 1

the table of elements also called Mendeleev's table or periodic table
classifies the atoms according to their properties.
They are disposed in columns and lines . On a column you find elements which have the same number of electrons on their external shell called valence shell and consequently the same
chemical properties . Example : on column completely on the right you find elements which have the external shell completed and so no chemical affinity with any elements : the noble gazes.

On a line you find elements which have the same external shell

For radioactivity, you must now that heavy elements with atomic number of 84 or more are all radioactive. Their nucleus is not stable and emits a particle (alpha, beta, gamma) . This is the phenomena of radioactivity

I must however explain that elements 43 and 61 are also radioactive

Answer 2

The periodic table of the chemical elements is a tabular method of displaying the chemical elements, first devised in 1869 by the Russian chemist Dmitri Mendeleev. Mendeleev intended the table to illustrate recurring ("periodic") trends in the properties of the elements. The layout of the table has been refined and extended over time, as new elements have been discovered, and new theoretical models have been developed to explain chemical behavior. Various layouts are possible to emphasize different aspects of behavior; the most common forms, however, are still quite similar to Mendeleev's original design.

It's connection is with radioactivity varies from one group to another. Basically, the first and the 17th group is the most active because of their elctron configuration is order to achieve octet configuration. The first group's radioactivity increases with the elements below while group 17 vice versa.

I hope this helps. :)

Answer 3

As a bio-chem undergrad. I find that I didn't memorize the first two rows the table on purpose. Memorization of the first two rows come from doing homework problems over and over again. By the time you get thru introductory and general chemistry, you'll at least know the atomic number and mass of H, N, C, and O in the back of your head. Probably even a few other elements such as Cl, Fl, B, S, I, Na, Li, Fe..etc.. But a few of my instructors has mentioned, except for a few mostly used elements, the rest of the periodic table should be used as tools, not memorized.