Use the following information to write the element in isotope notation. 11p^+,11e^-,12n^0 11 Na 22.99 What is the mass number? ] a ]

## Step1: The given information describes the composition of an atom. The notation , , and refers to protons, electrons, and neutrons, respectively. ## Step2: The atomic number, also known as the proton count (represented as ), is 11. As atoms are electrically neutral, the number of electrons (represented as ) is also 11. According to the question, the neutron count (represented as ) is 12. ## Step3: The isotope notation ( ) for this atom can be found by substituting these values, where Z is the proton count while A denotes the mass number. ### The mass number is determined by adding the number of protons and neutrons, which is .