1. When Mendeléev started his work, 63 elements were known. 2. He examined the relationship between the atomic masses of the elements and their physical and chemical properties.
1. When Mendeléev started his work, 63 elements were known.
2. He examined the relationship between the atomic masses of the elements and their physical and chemical properties.
Fill in the blanks: The basis of modern Periodic table is _______________
Properties of elements are periodic function of their atomic number.
Properties of elements are periodic function of their atomic number.
See lessFill in the blanks: Group 17 elements are called ______________
Yes it halogen.
Yes it halogen.
See lessWhy do you think the noble gases are placed in a separate group?
These are least reactive gasses.
These are least reactive gasses.
See lessWhat were the criteria used by Mendeleev in creating his Periodic Table?
1. When Mendeléev started his work, 63 elements were known. 2. He examined the relationship between the atomic masses of the elements and their physical and chemical properties.
1. When Mendeléev started his work, 63 elements were known.
See less2. He examined the relationship between the atomic masses of the elements and their physical and chemical properties.
Besides gallium, which other elements have since been discovered that were left by Mendeleev in his Periodic Table? (any two)
In NCERT Gallium, Scandium and Germanium are given but more elements are there which are discovered later.
In NCERT Gallium, Scandium and Germanium are given but more elements are there which are discovered later.
See less