Question

O

Answer 1

Answer:

The second and third option are isotopes of Bromine

Z=  35 A = 79

A = 79  N= 44

Explanation:

Step 1: What are isotopes ?

⇒ Elements  with same atomic number (Z) ( this means the same number of electrons and protons) but a different number of neutrons (N)

The atomic number (visible on the periodic table) is the number of protons.

The atomic mass is  the sum of the protons (Z) and neutrons (N), and is showed as 'A'. So A = Z+N

If we look at the periodic table, we can see that the atomic number of bromine (Z) = 35. This means the amount of protons = 35. Since isotopes have the same amount of protons, all isotopes of bromine, have 35 protons.

1) Z = 79, A = 196

Z = protons = electrons .So this element has 79 protons, as well as 79 electrons.

196 = 79 + N ⇒ N = 196 - 79 = 117 neutrons

⇒Since it doesn't have 35 protons, it isn't an isotope of Bromine, but of Gold (Au): 196Au

2) Z = 35 , A = 79

Z = protons = electrons .So this element has 35 protons, as well as 35 electrons.

79 =35 + N ⇒ N = 79 - 35= 44 neutrons

⇒Since it does have 35 protons, it is an isotope of Bromine. This isotope has 44 neutrons

⇒ This is 79Br, which is a stable isotope of Bromine.

3) A=79, N = 44

Z = A - N ⇒ Z = 79 - 44 = 35

Z = protons = electrons .So this element has 35 protons, as well as 35 electrons. It also has 44 neutrons.

⇒Since it does have 35 protons, it is an isotope of Bromine, with 44 neutrons: 79Br

4) Z = 44, N = 44

Z = protons = electrons .So this element has 44 protons, as well as 44 electrons.

A = 44 + 44 ⇒ A = 88  

⇒Since it doesn't have 35 protons, it isn't an isotope of Bromine, but of Ruthenium (Ru) : 88Ru

⇔So the second and third option are isotopes of Bromine