Lewis Acid

Wrought Iron is the purest form of iron. It contains 0.12 to 0.25% carbon and so it is the purest form of iron

Cesium

Catalytic converters are made from platinum or a similar, platinum-like metal, such as palladium or rhodium. A catalytic converter is an exhaust emission control device that reduces toxic gases and pollutants in exhaust gas from an internal combustion engine into less toxic pollutants by catalyzing a redox reaction (an oxidation or reduction reaction).

As an explosive

A pain killer

Crystallization of table salt from sea water

Explanation:

Gypsum is known as calcium sulphate ..(Cas(o)4)..

It contains calcium about 23.3 %..

Rest of the options have not contains calcium..

So the correct answer is GYPSUM..

Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.

Atoms

Lavoisier

Modern global warming is the result of an increase in magnitude of the so-called greenhouse effect, a warming of Earth’s surface and lower atmosphere caused by the presence of water vapour, carbon dioxide, methane, nitrous oxides, and other greenhouse gases.

Hydrogen Bomb is based on the principle of Nuclear Fusion

• Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles.

• The difference in mass between the reactants and products is manifested as either the release or absorption of energy.

Slight radioactivity of Banana is due to presence of K-40.

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

Sulphur

Pune

One mole of CO2 has mass of 44 g and 32 g of O2. So 16 g of O2 have 22 g of CO2 or 0.5 moles of it.