What is the shape of rhombic sulphur?

Which metal is available in the highest proportion on the earth's crust?

Give the composition of the alloys brass and bronze.

Define alloys. List the properties of alloys that make them useful over pure metals. Explain this fact with suitable examples.

$A$ non-metal $X$ exists in two different forms $Y$ and $Z$. $Y$ is the hardest natural substance, whereas $Z$ is a good conductor of electricity. Identify $X$, $Y$ and $Z$.

$A$ metal $M$ forms an oxide having the formula $M_{2}O_{3}$. It dissolves in both dilute sulphuric acid and dilute sodium hydroxide solution. Identify the metal and write the chemical equations for the reactions involved.