1. ChemCatalyst 10/23/15 Today you need your notebook and Laptop. Open the PowerPoint on the weebly. In your notebook answer the following questions: 1.What two particles does the nucleus contain? 2.Which subatomic particle has the smallest mass? 3. What is the electrical charge of a proton? Electron? Neutron?

2. The Atom: Calculating Protons, Neutron, and Electrons Chemistry/Pre-AP Chemistry Ms. Lizette Gutierrez Austin High School

3. Periodic Table Information Atomic Symbol Atomic Symbol Shorthand notation of one (uppercase) or two letters (1 uppercase and 1 lowercase) for an element Derived from the scientific names of the chemical elements S for sulfur Cl for chlorine Zn for zinc Some date back to Latin names Au (aurum) for gold Pb (plumbum) for lead. Others are named for people or places Es, Einsteinium for Einstein Cf, Californium for California Md, Mendelevium for Mendeleev

4. Periodic Table Information Atomic Number Discovered around 1913 by a Scientist name Henry Moseley Atomic Number is the number of protons in the nucleus of an atom. The atoms of each element differ from the atom of the element before it by one proton. In atoms that are electrically neutral, atomic number also is the number of electrons.

5. Periodic Table Information Atomic Mass Atomic Mass (mass number) – the mass of an individual atom of a particular element. – Units are in amu (atomic mass units) It was determined that the nucleus accounts for almost all the mass of the atom. Both the proton and the neutron are about 2,000 times more massive than a tiny electron.

6. Using the Periodic Table to Calculate Protons, Neutrons, and Electrons of an Atom

7. Classroom Example #1 Calculate the Number of p, n, and e for Lithium? Number of protons = 3 Number of electrons = 3 Number of neutrons 7 (6.941) – 3 = 4

8. Classroom Example #2 # protons = # electrons = # neutrons = 12 24 -12= 12

9. Classroom Example #3 # protons = # electrons = # neutrons = 18 40 -18= 22

10. Classroom Example #4 # protons = # electrons = # neutrons = 36 84 -36= 48