Understanding Neutrons and Electrons in Iridium Isotopes

What is the number of neutrons and electrons for a neutral isotope of iridium (Ir) with a mass number of 191?

A) 77 neutrons and 114 electrons

B) 114 neutrons and 77 electrons

C) 191 neutrons and 114 electrons

D) 191 neutrons and 77 electrons

Answer:

The correct answer is A) 77 neutrons and 114 electrons.

When dealing with a neutral isotope of iridium (Ir) with a mass number of 191, we need to determine the number of neutrons and electrons in the atom. In this case, the correct combination is 77 neutrons and 114 electrons.

The atomic number of iridium is 77, representing the number of protons in the atom's nucleus. Since the isotope is neutral, the number of electrons is also 77 to balance the charge.

To find the number of neutrons, subtract the atomic number (77) from the mass number (191): 191 - 77 = 114. Therefore, the isotope contains 77 neutrons and 114 electrons to maintain neutrality.