Question

this is how osmium appears in the periodic table. rounded to the nearest whole number, how many neutrons, on average, are in an atom of osmium? 76 114 190 266

Explanation:

Step1: Recall the formula for the number of neutrons

The number of neutrons \(N\) in an atom is given by \(N = A - Z\), where \(A\) is the mass number (approximate atomic mass) and \(Z\) is the atomic number.

Step2: Identify \(A\) and \(Z\) for osmium

From the periodic - table entry, the atomic number \(Z = 76\) (the top number) and the atomic mass \(A\approx190\) (rounded \(190.23\) to the nearest whole number).

Step3: Calculate the number of neutrons

Substitute \(A = 190\) and \(Z = 76\) into the formula \(N=A - Z\). So \(N=190 - 76=114\).

Answer:

114 (the second option)