PUMICE<span>: An </span>igneous<span>-volcanic rock, it is a porous, brittle variety of rhyolite and is light enough to float. It is formed when magma of </span>granite<span> composition erupts at the earth's surface or intrudes the crust at shallow depths. It is used as an abrasive material in hand soaps, emery boards, etc.</span>
A chemical compound can be described as substance composed of atoms from more than one element held together by chemical bonds in a fixed stoichiometric proportion. A compound has different physical and chemical properties from its constituent elements.
For example : compound water is made up of H and O bonded together and it has different properties from O and H.
Thus, among the given options, the one coreectly describing a compound is
a) The atoms are bonded together, and the compound has different physical and chemical properties than the individual elements.
Answer:
Acid + Base ------> Salt + Water
Example:
HCl + NaOH ------> H2O + NaCl