Pleas please help You have learned that the atomic number of a chemical is the number of protons found in the nucleus. Atomic numbers can be used to find the number of neutrons and electrons in an atom. In this project, you will practice atomic mass and atomic mass number calculation as well as fill out a chart using the periodic table. Don’t forget to read through the rubric below, so you will know what you will be graded on. When you are ready, upload it replacing the “Lastname” in the saved document name with your last name.
Part I:
The atomic number of the sodium atom is 11. The atomic mass number can be estimated by rounding the atomic mass to 23. From this information, you can find the number of neutrons: 11 protons plus how many neutrons equals a mass number of 23? The number of neutrons would have to be the difference between 23 and 11, which is 12. This fact can be restated this way: 11 protons plus 12 neutrons equals a mass number of 23. For every proton in the nucleus, an electron revolves around the nucleus. Since 11 protons are in sodium, 11 electrons must be in sodium.
Using this information and the Periodic Table from lesson titled Periodic Table fill in the chart below.

Element Atomic Number Atomic Mass How many neutrons? How many electrons? How many protons?
Sodium 11 23 12 11 11
Chlorine
Carbon
Lead
Iron
Magnesium
Uranium
Cobalt
Calcium
Platinum
Phosphorus