Metals and Non Metals_X

Calamine is an ore of

• Ca

• Fe

• Zn

• Cu

The reaction of zinc with dilute and concentrated nitric acid, respectively, produces:

• NO₂ and NO

• NO and N₂O

• NO₂ and N₂O

• N₂O and NO₂

In general, anodizing is a process of forming a thick oxide layer of ---------------------

• aluminium

• iron

• cobalt

• manganese

The reaction of calcium with water is less violent. When calcium reacts with water it starts floating because -

• the bubbles of hydrogen gas formed stick to the surface of the metal.

• Calcium is lighter than water

• At higher temperature, the density of calcium decreases

• None

Which of the following does not react with cold water?

• Na

• K

• Li

• Mg

Which of the following will not react with steam?

• Mg

• Fe

• Al

• Cu

Which of the following metals react with dilute nitric acid to evolve H₂ gas?

• Mg and Mn

• Zn and Fe

• Na and K

• Ca and Mg

Which of the following would have the least electrical conductivity?

• Silver

• Copper

• Silicon

• Oxygen

As one moves top to down in a periodic table, metallic nature ---------------

• increases

• decreases

• remains the same

• None

Iron does not burn on heating but iron filings burn vigorously when sprinkled in the flame of the burner. The reason behind this is:

• iron filings have different chemical composition than iron

• iron filings are non magnetic in nature

• iron filings have larger surface area

• iron filings are less reactive