Standard Atomic Notation F 19 Mass Number: Fluorine has a total of 19 protons and neutrons 9 Atomic Number: Fluorine has 9 protons Therefore fluorine has 19 – 9 = 10 neutrons Since atoms have no net charge it must have as many electrons as it does protons.

Activity: What does Standard Atomic Notation Tell Us? Standard Atomic Number Name of Element Atomic Number Mass Number Number of Electrons Number of Protons Number of Neutrons carbon 6 12 sulfur 16 calcium 40 20 nitrogen 7 14 molybdenum 96 42 18 C 12 6 Zn 65 30 V 51 23 In 115 49

Atomic and Mass Numbers Atomic Number 9 1- Ion charge(s) F Symbol Name Fluorine 19.00 Atomic Mass Mass Number 19 Atomic Number = the number of protons in the nucleus Mass Number = the whole number sum of the of protons and neutrons in the nucleus Atomic Mass = the mass of the atom weighted across its isotopes

Atomic and Mass Numbers H Hydrogen 1 1.0079 1+ Atomic Number Symbol Name Atomic Mass Ion charge(s) Mass Number Atomic Number = the number protons in the nucleus Mass Number = the whole number sum of the of protons and neutrons in the nucleus Atomic Mass = the mass of the atom weighted across its isotopes

Representing Atoms with Diagrams We represent atoms using Bohr-Rutherford models What is a Bohr-Rutherford model? What information is captured in a Bohr-Rutherford model? 15 p+ 16 n0 Phosphorus atom 15 protons 16 neutrons 15 electrons

Representing Atoms with Diagrams x p+ y n0 third electron orbital: can hold up to 8 electrons inner most electron orbital: can hold up to 2 electrons x protons in the nucleus y neutrons in the nucleus second electron orbital: can hold up to 8 electrons NOTE: # protons may = # neutrons NOTE: # protons = # electrons

Representing Atoms with Diagrams Hydrogen Helium Lithium Beryllium Boron Carbon

Periodic Table of Elements 1 15 16 17 18 8 9 10 11 12 13 14 2 3 4 5 6 7 Periodic Table of Elements