Question
A monoatomic anion (A^-) has 45 neutrons and 36 electrons. Atomic mass, group in the periodic table and physical state at room temperature of the element (A) respectively are
JEE Main
Chemistry
Structure of Atom
2026
JEE Main 2026 (04 April Shift 1)
JEE Main Chemistry Question (2026) — Solution
Options
- A. 80, 17, liquid
- B. 81, 16, solid
- C. 80, 16, gas
- D. 81, 15, gas
Answer
A. 80, 17, liquid
Step-by-step solution
Number of electrons in A^ - is 36. Number of electrons in neutral atom A = 36 - 1 = 35. Atomic number of A = 35. Number of protons in A = 35. Atomic mass of A = Number of protons + Number of neutrons = 35 + 45 = 80. The element with atomic number 35 is Bromine ( Br ). Bromine belongs to Group 17 of the periodic table. The physical state of Bromine at room temperature is liquid. Answer: 80, 17, liquid
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