2016 · Q45
Which one of the following statements is not correct?
General KnowledgeChemistry
- AAtoms of different elements may have same mass numbers
- BAtoms of an element may have different mass numbers
- CAll the atoms of an element have same number of protons
- DAll the atoms of an element will always have same number of neutrons
Explanation
Atoms of an element can have different numbers of neutrons; these are isotopes (e.g. carbon-12 and carbon-14). Hence the claim that all atoms of an element will always have the same number of neutrons is not correct. The other statements are true: different elements can share a mass number (isobars, e.g. 40Ar and 40Ca), atoms of one element can differ in mass number (isotopes), and every atom of an element has the same number of protons (its atomic number). The incorrect statement is (D).