Match List-I with List-II
| List-I | List-II | ||
|---|---|---|---|
| (Elements) | (Atomic Mass (u)) | ||
| (A) | Oxygen | (I) | 12 |
| (B) | Carbon | (II) | 23 |
| (C) | Calcium | (III) | 16 |
| (D) | Sodium | (IV) | 40 |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A)-(III), (B)-(I), (C)-(IV), (D)-(II)
Atomic mass is given in atomic mass units (u), one-twelfth of the mass of a carbon-12 atom. Rounded to a whole number, it equals the number of protons plus neutrons in the common atom of the element.
(A) Oxygen — this matches (III) 16. An oxygen atom has 8 protons and 8 neutrons.
(B) Carbon — this matches (I) 12. A carbon atom has 6 protons and 6 neutrons; carbon-12 is the standard that defines the unit.
(C) Calcium — this matches (IV) 40. A calcium atom has 20 protons and 20 neutrons.
(D) Sodium — this matches (II) 23. A sodium atom has 11 protons and 12 neutrons.