Give the correct number of protons, neutrons and electrons for the following isotope:.

• A. 35 protons, 35 neutrons, 81 electrons
• B. 35 protons, 46 neutrons, 36 electrons
• C. 81 protons, 46 neutrons, 82 electrons
• D. 35 protons, 46 neutrons, 34 electrons

Answer: (B)

Verified step by step guidance

1. Identify the element from the symbol 'Br'. 'Br' stands for Bromine, which is an element in the periodic table.
2. Determine the number of protons. The atomic number, which is the lower number (35) in the isotope notation, represents the number of protons in the nucleus of the atom. Therefore, Bromine has 35 protons.
3. Calculate the number of neutrons. The mass number, which is the upper number (81) in the isotope notation, is the sum of protons and neutrons. To find the number of neutrons, subtract the number of protons from the mass number: 81 - 35.
4. Determine the number of electrons. Since the isotope is represented as Br⁻, it indicates that the atom has gained one extra electron compared to the neutral atom. A neutral Bromine atom would have 35 electrons (equal to the number of protons), so Br⁻ has 35 + 1 electrons.
5. Summarize the findings: The isotope has 35 protons, the calculated number of neutrons from step 3, and 36 electrons as determined in step 4.