Atomic+Number,+Mass+Number,+Nuclides





An **atomic number** is the number of protons found in the nucleus of an atom. Each element has a different number of protons and each element has the same number of protons so the atomic number can identify the element an atom belongs to. As you go right to left and up to down on the periodic table the atomic number increases. It's commonly represented by the symbol **Z**. "Atomic number" in German is "Atomzahl", so the Z symbol for atomic number probably comes from "Zahl" (number). In an atom of neutral charge, atomic number is equal to the number of electrons.  

In this diagram the atomic number is A. Titanium has 22 protons so that is its atomic number.

The **mass number** is the sum of the number of protons and neutrons in the nucleus. It references all the particles that have mass in the atom thats why it is called the mass number. The mass number is different for each different isotope of a chemical element. -In the diagram the mass number is not shown but the mss number for titanium is 44.

A **nuclide** is an atom of a specific isotope. An example of a nuclide is 13C which is a type of isotope of carbon. So it is 13C nuclide.







-This is an example of nuclide notation for a sodium ion.

http://www.hferrier.co.uk/standard/topic3/nuclide.gif

http://www.bcscience.com/bc9/images/0_quiz_element.gif

http://en.wikipedia.org/wiki/Atomic_number

http://www.atomicarchive.com/Physics/Images/isotopes.jpg

http://antoine.frostburg.edu/chem/senese/101/history/faq/why-is-atomic-number-Z.shtml