#1 The main constituents of pearls are
#2 Amalgams are
An amalgam is an alloy of mercury with another metal, which may be a liquid, a soft paste or a solid, depending upon the proportion of mercury. … Silver-mercury amalgams are important in dentistry, and gold-mercury amalgam is used in the extraction of gold from ore.
#3 Which of the following is the lightest metal?
It is a soft, silvery-white alkali metal. Under standard conditions, it is the lightest metal and the lightest solid element. Like all alkali metals, lithium is highly reactive and flammable, and must be stored in mineral oil.
#4 Which metal pollute the air of a big city?
That’s why big cities are polluting by air pollution. Lead is lavish in polluting the ambient area of cities because it has heaviest particulate to react time and again quickly.
#5 Bell metal is an alloy of
Bell metal is a hard alloy used for making bells and related instruments, such as cymbals. It is a form of bronze with a higher tin content, usually in approximately a 4:1 ratio of copper to tin (typically, 78% copper, 22% tin by mass).