Give reason : the atom of the element produce more than one spectral line.

answer:

when atoms are excited they emit light of certain wavelengths which correspond to  different  colors. each  element produces  a unique set of  spectral lines. since no two  elements  emit the same  spectral lines,  elements  can be identified by their line spectrum.

the answer is b. dilution

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).