Metallurgy

In order to reduce zinc metal from its oxide (a)   is used.

Type you answer:

Name the powders added to lower the melting point of alumina. (Name only. Don't write the formulae)

(a)  

In Bayer's Process impurities like (a)   are removed when the ore is reacted with concentrated caustic soda.

Mercury,silver,gold are very reactive metals

• True

• False

What property defines a metals ability to withstand twisting, bending, stretching, or deformation without breaking.

• Hardness

• Brittleness

• Ductility

• Toughness

According to the reactivity of metals----------------------------

• Zn <Al <Fe <Cu

• Al< Fe< Cu <Zn

• Al< Fe< Zn <Cu

• Cu< Fe< Zn <Al

Two highly reactive metals are

• Na and K

• Cu and Fe

• Ag and Au

• Al and Zn

Ores contain metal compounds with some of the impurities like soil,sand,rocky material etc. These impurities are called as------------------

• Minerals

• Gangue

• Metallurgy

• corrosion

Sulphide ores are concentrated using ______ method.

• Wilfley Table

• Hydraulic Separation

• Magnetic Separation

• Froth Floatation

• Leaching

What is the colour of the flame when sodium metal is heated?

• RED

• YELLOW

• GREEN

• WHITE