question_answer 27)

  Which of the following statements is not true about an atom? (a) Atoms are not able to exist independently (b) Atoms are the basic units from which molecules and ions are formed (c) Atoms are always neutral in nature (d) Atoms aggregate in large numbers to form the matter that we can see, feel or touch

Answer:

  (d) This statement is not true The correct statement is as The molecules and ions aggregate together in large number to form the matter. We cannot see the individual molecules/ions with our eyes. only we can see the various substances which are a big collection of molecules/ions, So, option (d) is incorrect. Atoms of most of the elements are chemically very reactive and do not exist in the free state. The atoms of only noble gases are chemically uncreative and exist in free state. Atoms usually exist in the two forms (i) molecules and (ii) ion's Therefore, atoms are the basic unit from which molecules and ions are formed. When atoms form molecules or ions, they become stable because they acquire the stable noble gas electron arrangement. Therefore, they are neutral in nature