SSC CHSL GK Questions 2026

The Pir Panjal is the longest and most important range of the Lesser or Himachal Himalaya, running from the Jhelum through Jammu and Kashmir towards Himachal Pradesh and separating the Kashmir valley from the Jammu plains.

The Himalayas were raised when the northward-moving Indian plate collided with the Eurasian plate and the sediments of the shallow Tethys Sea between them were compressed into great folds and thrust upward.

Kanchenjunga rises to 8,586 metres on the Sikkim-Nepal border and is the highest peak in India's undisputed territory, as well as the third highest in the world after Everest and K2.

Nathu La lies in eastern Sikkim on the old trade route from Gangtok to Lhasa and is one of the passes on India's border with the Tibet region of China; Jelep La, also in Sikkim, is the other.

Bhangar is the older alluvial deposit of the Northern Plains. It forms terraces that stand above the present flood level, so fresh silt no longer reaches it, and long leaching has left calcareous concretions called kankar in its profile.

The Bhabar is a narrow belt about 8 to 16 kilometres wide, laid along the foot of the Shiwalik range, where the rivers leaving the hills drop their coarsest load.

Karewas are thick beds of glacial clay, silt and other lake sediments laid down in the Kashmir valley, which lies between the Pir Panjal and the Greater Himalaya.

Duns are flat-floored longitudinal valleys formed where rivers coming out of the Lesser Himalaya were held up behind the rising Shiwalik and filled the depression with gravel and silt.

The Himadri is the innermost and northernmost of the three parallel Himalayan ranges, with an average height of about 6,000 metres.

Mendeleev arranged the elements by increasing atomic mass in 1869 and left blank spaces where his pattern demanded an element that was not yet known.

After discovering the electron in 1897, J. J. Thomson pictured the atom as a sphere of positive charge with negatively charged electrons stuck in it, a picture often compared to plums in a pudding or seeds in a watermelon.

Isotopes are atoms of the same element, so they have the same number of protons and therefore the same atomic number, but they carry different numbers of neutrons, which makes their mass numbers differ.

The modern periodic table has seven horizontal rows, called periods, and eighteen vertical columns, called groups.

John Newlands arranged the fifty-six elements known in 1866 in order of increasing atomic mass, beginning with hydrogen, the lightest, and ending with thorium, the fifty-sixth.

Henry Moseley showed in 1913, from the frequencies of the X-rays that elements emit, that the atomic number, the number of protons in the nucleus, is the more fundamental property of an element.

Electronegativity is the tendency of an atom to attract a shared pair of electrons towards itself. It increases from left to right across a period, as nuclear charge grows, and decreases down a group, as each new shell puts the outer electrons further from the nucleus.

The alkali metals are lithium, sodium, potassium, rubidium, caesium and francium. Each has a single electron in its outermost shell, loses it readily to form a positive ion, and therefore stands in group 1 of the modern periodic table.

The capacity of a shell is given by the formula 2n squared, where n is the number of the shell counted outward from the nucleus.

Most alpha particles passed straight through the foil, a few were deflected through small angles and about one in twenty thousand bounced back.

James Chadwick discovered the neutron in 1932 by bombarding beryllium with alpha particles and showing that the radiation produced consisted of neutral particles of nearly the same mass as the proton.