Chemistry Online Quiz

Galena is a lead sulfide mineral with a chemical composition of PbS. It is the primary ore of lead and is often mined for its silver content.

The main gases responsible for the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapor (which all occur naturally), and fluorinated gases (which are synthetic). Bacteria are responsible for both the production and consumption of greenhouse gases such as carbon dioxide (CO₂), nitrous oxide (N₂O) and methane (CH₄).

The colour of the most popular emerald is pure deep green. Emerald is a gemstone and a variety of the mineral beryl (Be₃Al₂(SiO₃)₆) coloured green by trace amounts of chromium or sometimes vanadium.

Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and halons destroy the earth's protective ozone layer, which shields the earth from harmful ultraviolet rays generated from the sun. CFCs and HCFCs also warm the lower atmosphere of the earth, changing global climate.

The main gases responsible for the greenhouse effect include water vapor, carbon dioxide, methane, nitrous oxide, and water vapor (which all occur naturally), and fluorinated gases (which are synthetic) chlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, bromofluorocarbons (halons), perfluorcarbons, nitrogen trifluoride, and sulphur hexafluoride.

Silver is not present in German silver. German Silver is an alloy of copper (60%), zinc (20%) and nickel (20%). It is named for its silver-white colour. It is used for making daily utensils and jewellery.

The product used for manufacturing of Industrial alcohol is Molasses. Ethanol is the major product obtained from molasses by means of anaerobic fermentation using microorganisms.

Most iron is found in minerals formed by the combination of iron with other elements. The purest form of iron is Wrought iron. It contain 99.5% iron, 0.25% carbon and 0.25% other impurities.

Combustion is a chemical process. It is a chemical reaction between substances, usually including oxygen and usually accompanied by the generation of heat and light in the form of flame.

The graphite bricks act as a moderator. They reduce the speed of neutrons and allow a nuclear reaction to be sustained.