(A) Mass number (X)
(B) Atomic mass (X)
(C) Relative abundance ()
(D) all of the above (X)

Answers: The properties of an element mosly corresponds to that isotope which has greater Relative abundance.

(A) NaCl (X)
(B) H2O (X)
(C) CCI4 (X)
(D) It can be applied to all mentioned above ()

Answers: It can be applied to all mentioned above.

(A) lighter ()
(B) intermediate (X)
(C) heavier (X)
(D) are collected at same time (X)

Answers: lighter

(A) different number of protons (X)
(B) same number of neutrons (X)
(C) different number of neutrons ()
(D) same mass number (nucleon number) (X)

Answers: Isotopes of the same elements has different number of neutrons.

(A) sand (X)
(B) haemoglobin (X)
(C) diamond (X)
(D) maltose ()

Answers: maltose

(A) mass of an atom itself is in fraction (X)
(B) atomic masses are average masses of isobars (X)
(C) atmoic masses are average masses of isotopes proportional to their relative abundance ()
(D) atmoic masses are average masses of isotopes (X)

Answers: Mostly elements have fractional atomic masses because of atmoic masses are average masses of isotopes proportional to their relative abundance.