Name a non-metal which is lustrous and a metal which is non-lustrous.

Give reasons for the following:
$(i)$ Ionic compounds have high melting and boiling points.
$(ii)$ Ionic compounds are soluble in water.
$(iii)$ Ionic compounds are solid and somewhat hard.
$(iv)$ Ionic compounds conduct electricity in the molten state.
$(v)$ Metals have a tendency to lose electrons.

What is the proportion of gold and copper in $22$ carat gold ornaments?

Alloys are homogeneous mixtures of a metal with a metal or non-metal. Which among the following alloys contains a non-metal as one of its constituents?

Generally, metals react with acids to produce salt and hydrogen gas. Which of the following acids does not produce hydrogen gas when reacting with most metals (except $Mn$ and $Mg$)?

Which metal burns with a dazzling white light when heated at a high temperature?