Ch 8Elements of Group 1 and 2 — Class 11 Chemistry, concept-first.

Groups 1 and 2 both belong to the s-block of the periodic table, since in every element of these two groups the last electron added enters an 's' subshell.

Groups 1 and 2 both belong to the s-block of the periodic table, because in each of their elements the last (highest-energy) electron added enters an 's' subshell.

In its free (uncombined) state, hydrogen occurs as dihydrogen gas, H2. Hydrogen is the single most abundant element in the entire universe, making up roughly 70% of the universe's total mass, and it i…

Where hydrogen belongs in the periodic table has long been debated, because its single-electron configuration, 1s¹, can be read two different ways.

Isotopes are atoms of the same element — meaning they share the same number of protons, and so the same atomic number — that differ from one another in mass number because they carry different numbers…

Dihydrogen can be prepared by several routes, split broadly into laboratory-scale and industrial-scale methods. A.

A. Physical properties: dihydrogen is a colourless, odourless, tasteless gas that burns with a pale blue flame; it is non-polar, essentially insoluble in water, and lighter than air. B.

Dihydrogen's largest single industrial use is in manufacturing ammonia. It is also used to make vanaspati ghee by the catalytic hydrogenation of vegetable oils; as a rocket fuel in its liquefied form;…

Groups 1 and 2 sit on the far left of the periodic table; in both, the last electron added enters an 's' subshell, which is why both belong to the s-block.

Every group 1 element has the general outer electronic configuration ns¹, and every group 2 element has ns².

Both groups share a broad physical character: the alkali metals are silvery-white and soft, and because of their comparatively large atomic size they have low densities — they are, as a group, the mos…

Both the alkali metals and the alkaline earth metals are highly reactive, which is exactly why they are always found in nature already combined with other elements rather than free.

It might be expected that every element within a single group should show a smooth, regular gradation of properties — but the first member of group 1 (lithium) and the first member of group 2 (berylli…

Group 1: lithium metal is used in the long-life batteries found in digital watches, calculators and computers; liquid sodium is used as a heat-transfer medium in nuclear power stations; potassium chlo…

Group 1: sodium ion is present in the largest supply of all ions in extracellular fluids, which serve as the medium that transports nutrients to the body's cells; the concentration of sodium ion in th…

Sodium carbonate, familiar as washing soda, Na2CO3.10H2O, is manufactured commercially by the Solvay process.

Sodium hydroxide, caustic soda, NaOH, is manufactured commercially by electrolysing a saturated aqueous solution of sodium chloride (brine) in a Castner-Kellner cell, which uses a mercury cathode and…

Calcium carbonate, CaCO3, occurs naturally as chalk, limestone and marble. It can be prepared in two ways: (i) by bubbling carbon dioxide through a solution of calcium hydroxide (slaked lime), which p…

Hydrogen peroxide, H2O2, is a low-cost, clean, mild oxidising agent, commercially sold as a 30% aqueous solution.

Lithium aluminium hydride, commonly abbreviated LAH, has the formula LiAlH4. It is prepared by reacting lithium hydride with aluminium chloride, 4LiH + AlCl3 → LiAlH4 + 3LiCl.