Question

determine the number of protons, electrons, and neutrons for each isotope. 5. an isotope has atomic number 19 and a mass number of 39. p=__ e= n= 6. an isotope has 14 electrons and a mass number of 28. p= e= n= 7. an isotope has 21 neutrons and a mass number of 40. p= e= n=__ 8. what unit is the atomic mass reported in (look at your notes)? 9. how many protons and electrons does osmium have?

Explanation:

Step1: Recall atomic number = protons = electrons

For neutral atoms, number of protons (p) equals number of electrons (e). Atomic number gives proton - electron count.

Step2: Calculate neutrons

Neutrons (n) = mass number - atomic number.

Answer:

1. p = 19, e = 19, n = 39 - 19=20
2. p = 14, e = 14, n = 28 - 14 = 14
3. p = 40 - 21=19, e = 19, n = 21
4. Osmium (Os) has atomic number 76. So p = 76, e = 76, n needs more info on mass - number to calculate.