SILENTY BEGIN YOUR DO NOW – 5min50 minutes of valuable learningtime!!
Let’s review the Do Now
The Parts of the Atom e- p n 1- 1+ 0 Electron cloud around the nucleus nucleus nucleus 1/1,840 1 1
Which two particles are responsible for themass of an atom? Protons and NeutronsWhich two particles are responsible for thecharge of an atom? Protons and Electrons
26 Atomic Number Atomic Number Fe Iron 55.845 Atomic Mass Atomic MassAtomic Number = 26 26Atomic Mass = 55.845 55.845Mass # = 56 56# of Protons = 26 26# of Neutrons = 30 30# of Electrons = 26 26
Notes and Guided Practice
Different Elements—DifferentNumbers of Protons the number of protons The type of the number of electrons element
What are the atomic numbers of carbon, nitrogen and oxygen? Carbon = 6, Nitrogen = 7, Oxygen = 8Explain the difference between an oxygen atom and a carbon atom. Oxygen has 8 protons. Carbon has 6 protons.
Neutrons and Isotopes• Isotopes are atoms of the same element that have different numbers of neutrons. Most elements have several isotopes. Same Different
How do the carbon isotopes differ? Carbon isotopes have different numbers of neutrons
Atomic Number vs. Mass Number The number of The number of protons protons and neutrons Hint : # of neutrons = mass # - protons
Average Atomic MassThe average atomicmass of an element isthe average mass of theelement’s isotopes,weighted according tothe abundance of eachisotope.
How is the average atomic masscalculated? The abundance of each isotope is changed to decimal form. The mass of each isotope is multiplied by it’s corresponding decimal percentage. All the values are added together to determine the average atomic mass 0.989 x 12 = 11.868 0.0101 x 13= + 0.143 12.01