When the periodic table started the elemtns were sorted into atomic weightd Dmitri Mendeleev created a far sighted periodc table. You might be surprised to learn that there are several periodic tables that have been invented, the one that is commonly used is not the preference of everyone, and there have been variations of this including a circular periodic table.
The current standard periodic table is laid out in rows left to right, sometimes called periods, and columns. The elements are sometimes grouped together based on certain similiarities.
The story of Dmitri Mendelev who first proposed this current table is an extradoanry one of his mother traveling on horse back across Russia from Siberia to Moscow to enroll him in a school.
In 1869 he said he saw in a dream a table of all the elements laid out on a piece of paper, after organising 63 individual cards of the known elements at the time. By creating blank spots in the periodic table that wasn’t there previoiusly he couldt begin to predict the properties of elements that hadn’t been discovered yet.
He gave Gallium, element 31 a name when it hadn’t been discovered called “eka aluminum”. Eka meaning one in Sanskrit. Gallium was named after France because it was discovered by a Frenchman. This come from the old name for France being “Gaul”.
He also called element 32 “eka silicon” which later became known as Germanium, because as it was directly below aluminiumit was directly below Silicon in his periodic table.
He wrote a textbook called “Organic Chemistry”. Element 101 is named after him “mendelevium”. There have been over 800 Nobel prize winners, and only 15 scientists has an element named after him. While named after his death, some people still concede this is a great honour, which may go some way for him not having received a Nobel prize.
Before this John Newland, a British chemist presented his periodic table which was ridiculed for what he said in 1865 that if the chemical elements are arranged, with all known 57 elements in order of their atomic masses that every 8th element had a property similiar to the first. It only worked for lighter elements up to calcium at the time. It not include nobel (inert) gases because they were not discovered at the time.
When the periodic table was first laid out the noble gases had not yet been discovered as elements were stuided based on reactivity.
Once the periodic table was laid out properly, propeties of elemtns that weren’t ye tdiscovered were able to be predicated. The mnext two rows have 18 elements.
The periodic table lists all of the elements in increasing order of atomic number, in rows moving left to right. There are seven rows left to right, with the eight row being the moble gases.
of lanthanides, and actinidies respectfully.
It has 19 groups left to right, with the noble gases that have a full outer electron shell on as the furthest right column, and starting from left to right in order of how many valence electrons the atom has.
As you go down the periodic table elements will have more electrons so will have a greater atomic radius, that is a greater distance from the nucleus to the electrons on the outermost (also called the valence) shell.