Number of elements discovered to till date.

…………. defined an element as any substance that cannot be decomposed into further simple substance by physical or chemical change.

Lithium, …………………… and Potassium constitute a Dobereiner's triad

Louis Proust stated that……………….. atom is the building material.

Group of three elements with similar chemical properties is called …………….

Dobereiner triad is based on

According to this every 8th element has similar properties starting from a, given element

Newlands’ periodic table was restricted to …………….. elements.

The number of periods and groups in Mendeleeff’s periodic table is

Mendeleeff’s periodic table is based on

Atomic weight = ……………….. x equivalent weight

Element with atomic number 101 is

Example for anomalous pair

The number of positive charges (protons) in the atom of an element is called………

The atomic weight of a bivalent element is 9. The equivalent weight of same element is