Question

cobalt has a mass number of 59 and an atomic number of 27. a student wants to create a model of a cobalt atom. which statement about the model is correct? (1 point)
the model should show 32 protons and 59 neutrons.
the model should show 27 protons and 27 neutrons.
the model should show 27 protons and 32 neutrons.
the model should show 59 protons and 27 neutrons.

Explanation:

Step1: Recall the definitions

Atomic number = number of protons. Mass number = number of protons + number of neutrons.

Step2: Find the number of protons

Given atomic number \(Z = 27\). So, number of protons \(p=27\).

Step3: Find the number of neutrons

Given mass number \(A = 59\). Using the formula \(A=p + n\) (where \(n\) is the number of neutrons), we can solve for \(n\): \(n=A - p\). Substitute \(A = 59\) and \(p = 27\) into the formula: \(n=59 - 27=32\).

Answer:

The model should show 27 protons and 32 neutrons.