He arranged the elements in group of three such that atomic weight of middle element is average of first and third element. These elements resembled in their properties.
He could not classify all the elements discovered at the time into Iriads.
He arranged the elements in increasing order of their atomic weights and that any given element has similar properties to the eight element that followed it. The relationship was same as that existing between musical note and its octave.
He could not classify all the elements discovered at that time.
“The properties of the elements, as well as the formulae and properties of their compounds depend in periodic manner on the atomic weight of the elements”.
“The properties of elements, as well as the formulae and properties of their compounds are periodic functions of atomic number of the elements”.
The elements of group! (alkali metals), group 2 (alkaline earth metals) and group 13 to 17 constitute the representative elements. They are elements of s-block and p-block.
These are the elements of group 3 to 12 in the centre of the periodic table. They also called d-block elements. They have general electronic configuration (n-i) d1–10 ns0–2. They are metals. They show variable oxidation state and form coloured ions.
Lanthanoids (the fourteen elements after Lanthanum) and actinides (the fourteen elements after actinium) are called inner transition elements. Their general electronic configuration is (n – 2) t0–14 (n – 1)d0–2 ns2. They are also called f-block elements. They are all metals. They show variable oxidation states. Their properties are quite similar.
It is the energy required to remove an electron from an isolated gaseous atom in its ground state.
The reduction in force of attraction by the electrons of shells present in between nucleus and valence electrons is called screening effect or shielding effect. Greater the number of intervening electrons between valence electron and nucleus, the greater will be shielding or screeding effect.
Do follow NCERT text book and solve questions with the help of Physics Wallah NCERT solutions for class 11 chemistry. If any students need to take the online test to check their concepts or undertstanding then they can visit Quiz for Periodic Properties.
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