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Index (R)
RA - RC
RD - RF
RG - RJ
RK - RN
RO - RR
RS - RV
RW - RZ
Moment of truth
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The fastest man-made object that ever leave the Earth is the New Horizon spacecraft, launched in January 2006, and attained a speed of more than 36000 mph. |
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RO - RR
roasting Min. Ext.
A process in mineral extraction by heating an ore, usually a sulfide, in air to convert it to an oxide. For example, galena (lead sulfide) is heated in air to convert it to lead oxide:
which is then reduced by coke (carbon) in a blast furnace to give lead. The corrosive byproduct, sulfur dioxide (SO2), can be safely removed by allowing it to react with calcium carbonate.
rock salt Min.
Common name for the naturally occurring mineral sodium chloride. See halite.
Rose's metal Eng.
An alloy of bismuth (50%) that contains 25-28% lead snd 22-25% tin. It is a low-melting point, fusible alloy at 100°C. It is used in castings and mouldings.
RO - RR
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