Xenon, best known till a few years back as an inert gas filled inside incandescent lamps, is named after a Greek word, which means ‘stranger’. These days xenon, the rarest of the noble gases, is becoming increasingly familiar and is finding increased uses and usage in many fields.

The lithium-ion batteries needed to power electric cars use lithium carbonate or lithium hydroxide.

The scientist who first of all showed that the atomic number is more fundamental property of an element than its atomic mass was Henry Moseley. He is best known for the Moseley’s Law and contributions to Physics.

Permanent hardness of water cannot be removed by simple physical methods like boiling, filtering and distillation.

Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state.

” baking soda / cooking soda ” are the commercial names of sodium bicarbonate.

At RT i.e. 25 C, the density of water is 1 g/L.
Mass of water = Density x volume = 1 g/L x 0.0018 x 10^-3 L = 1.8 x 10^-3 g
18 g water = 1 mole
1mole water contains 6.023 x 1023 molecules of water
So, 18 g water cotains 6.023 x 1023 molecules of water
Then, 1.8 x 10^-3 g water contains 1.8 x 10^-3 x 6.023 x 10²³ / 18 g = 6.023 x 10¹⁹ molecules of water
===>> 6.023 x 10¹⁹

Gallium

1. Bromine and mercury( Br & Hg) are liquid at room temperature.
2. There are 4 other elements that melt a few degrees above room temperature. they are Francium, Caesium, Gallium and Rubidium.
3. Gallium a brittle solid at low temperatures, and a liquid at temperatures greater than 29.76 °C (85.57 °F) (slightly above room temperature). The melting point of gallium is used as a temperature reference point.
4. Thus gallium is liquid at room temperature.

gun powder is the mixture of potassium nitrate powdered charcoal and sulphur.

it does not carry any charge

setting of cement can be slowed.

Gypsum is a mineral and is hydrated calcium sulfate in chemical form. Gypsum plays a very important role in controlling the rate of hardening of the cement. During the cement manufacturing process, upon the cooling of the clinker, a small amount of gypsum is introduced during the final grinding process. Gypsum is added to control the “setting of cement”. If not added, the cement will set immediately after mixing water leaving no time for concrete placing.

Polytetrafluoro ethylene