John Alexander Newland develop the Octave rule in the year 1865.
- Newland prepared a table in Cobalt(27) and Nickel(28) were placed in the category of Halogen element.
- "Thorium" elements was the Last element in Newlands law's of octaves.
- According to Newlands law of octaves 56 element is exist in nature.
- Newland discovered that properties of every eighth element are the same as the first element.(sa re ga ma pa dha ni sa)
- Newlands octave rule applies only upto the Calcium(Ca) element.
*Dobereiner, Newlands and Mendeleev classification was based on ✔️Atomic mass.
- John Dobereiner divided the elements into groups of THREE based on their properties.
- This group are called Triacs or Triads.
- Li Na K represent a Dobereiner Triads.
- Phosphorus ,Arsenic, Antimony are Triplet.
The Periodic table was invented by Dmitry Mendeleev in 1869 Ad.
- He divided the periodic table into 9 groups and 7 periods.
- Mendeleev periodic table elements were arranged on basis of increasing atomic mass.
- 63 elements were known when Mendeleev begin his work.
- Mendeleev first scientist to make periodic table of elements.
- In Mendeleev periodic table the vertical column is called Groups.
- Mendeleev periodic table was published in a "German Magazine" in the year of 1872.
The classification of elements in the Modern periodic table is based on ✔️Atomic Numbers.
- Modern Periodic table elements arrange in increasing order of their atomic numbers.
- Modern Periodic table presented by Henry Moseley in 1913.
- 18 Groups and 7 Periods tools exist in the Modern periodic table.
- Fast element of the modern Periodic table is Hydrogen.
- Hydrogen and Helium is placed in First period.
- First Metal element in the Modern periodic table is Lithium.
- Modern Periodic table Noble Gases are placed in 18 groups (zero group).
- Modern Periodic table Inert Gases are placed in 18 group.
- Modern Periodic table Halogens are placed in 17 groups.
- First group represent Alkali Metals in Modern Periodic table.
- Second group represent Alkali Earth Metal in Modern Periodic table.
- In Modern Periodic table Metal are placed on the Left side.
- Noble gases are the Minimum Reactive element of the Modern periodic table.
- Lithium element has atomic number👉 3.
- The 6th period of the Modern periodic table content 32 Elements.
- Horizontal rows in a Periodic table called period.
- Second periods has represent Highest number of non metal in modern Periodic table.
- 56 Atomic number belongs to S - block.
- 57 Atomic number belongs to d - block.
- Lanthanides and Actinides are f - block element.
- Fluorine is the first element of group 17 in Modern Periodic table.
- Californium is a member of Actinium group.
- 57 Atomic number of Lanthanum.
- 58 Atomic number of Cerium.
- 89 Atomic number of Actinium.
- Lithium,sodium and potassium have in common is they have one electron in their Outermost shell.
- only Non metal present on the left in the Modern periodic table is Hydrogen.
- 58 to 71 are called Lanthanoids.
- 13 and 31 elements belonging to the same group in Modern Periodic table.
- Rubidium is the the very metallic element of 5th period in Modern Periodic table.
- In Modern Periodic table period 1 does not include Metals.
- 4 and 5 priods has two Metalloid.
- In Modern Periodic table Zig-Zag line separate Metals from Nonmetals.
- Phosphorus is Tetratomic element discovered by Henningbrand in 1969.
- 2nd and 3rd period has 8 elements each.
( FOR RRB NTPC, Railway Group d, SSC & ALL GOVT. EXAM PREPARATION)
Physics
Chemistry
Biology
Polity
Geography
History
Current affairs
Miscellaneous
- INDIAN RUPEES
- INDIA'S NATIONAL PARK AND WILDLIFE SANCTUARY
- BOOKS AND AUTHOR PART 1
- BOOKS AND AUTHOR PART 2
- NOBEL PRIZE 2020
- ORGANIZATION AND HEADQUARTER
