Question

1. how many neutrons does europium - 151 have? what is the isotopes mass number?

Explanation:

Step1: Determine the mass number

The mass number is given in the isotope name. For europium - 151, the mass number \(A = 151\).

Step2: Find the atomic number of europium

From the periodic table, the atomic number of europium \(Z=63\).

Step3: Calculate the number of neutrons

The formula for the number of neutrons \(N\) is \(N=A - Z\). Substitute \(A = 151\) and \(Z = 63\) into the formula: \(N=151-63\).

Answer:

The mass number is \(151\). The number of neutrons is \(88\).