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 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

Representing Atoms Hydrogen Helium Lithium Beryllium Boron Carbon