1. Chemistry– 4/28/2019 Objectives Bell Ringer – Review
3.3 Use the periodic table to determine the atomic number; atomic mass; mass number; and number of protons, electrons, and neutrons in isotopes of elements
3.4 Compare characteristics of isotopes of the same element
Calculate the weighted average atomic mass of an element from isotopic abundance, given the atomic mass of each contributor
Bell Ringer – Review
List the three subatomic particles and where their found in the atom.
Homework: Complete atomic number and mass worksheet
Study for subatomic particles quiz
Read chapter 4 and complete study guide

2. Atomic Structure
Nucleus – the center of an atom; made up of protons and neutrons
Proton – A positively charged subatomic particle in the nucleus of an atom
Neutron – A neutral subatomic particle in the nucleus of an atom
Electron – a tiny negatively charged subatomic particle moving around outside the nucleus of an atom

4. Properties of Subatomic Particles
Symbol
Electrical
Charge
Relative
Mass
Location
Electron e- 1-
1/1840
Orbiting the nucleus
Proton p+ 1+ 1
In nucleus
Neutron n0
Quiz on this information TOMORROW

5. Practice Problems Subatomic Particles Select the term that best matches the phrase
Symbolized by e-
Contains all the atom’s mass
Has a charge of 1-
Has no charge
Has a positive charge and a relative mass of 1
The center of an atom
Symbolized by n0
Cathode Ray
Electron
Nucleus
Neutron
Proton
Electron
Proton
Neutron
Nucleus

6. Atomic Structure
Atomic number – the number of protons in a nucleus of an atom of that element
Atomic (average) mass number – the number of protons plus the number of neutrons

7. Determining the number of subatomic particles
Atomic Mass Atomic number # of protons (p+) = atomic # # of electrons (e-) (in a neutral atom) = # of p+ # of neutrons (n0 ) = atomic mass (rounded) – atomic #
#p+ = 4
#e- = 4
#no = 9-4 = 5 9 Be 4

8. Atomic Structure
Isotopes – Atoms with the same number of protons but different number of neutrons.
Carbon-12 Carbon-14
#p+ = 6 #p+ = 6
#e- = 6 #e- = 6
#no = 12-6 = 6 #no = 14-6 = 8
Atomic Mass 12 C 14 6

9. Determine the #p+, #e-, and #no
Atomic Atomic
Element Symbol # Mass #p+ #e- #no
Lithium
Fluorine
Argon
Potassium-40
Hydrogen
He n/a
Ruthenium
Os-194 n/a