Introduction to the Atom What is the Structure

Introduction to the Atom

What is the Structure of the Atom? Electron Cloud

What are the 3 Subatomic Particles? Particle Symbol Mass (amu) Proton p 1 Neutron n Electron e- Location Charge Nucleus + 1 Nucleus No Charge 0 Electron Cloud -

Reading Your Periodic Table 6 C Carbon 12. 01 Atomic Number Symbol Element Name Average Atomic Mass

Important Definitions • Atomic Number -- number of protons in an atom Atomic # = p • Mass Number -- the sum of the protons and neutrons in an atom Mass # = p + n • Neutral Atom -- protons and electrons are equal p = e-

Symbolic Notation chemical symbol ___ protons ___ neutrons ___ electrons Reminder Atomic # = p Mass # = p + n p = e-

Atomic # = p Practice Mass # = p + n p = e- # of p 8 # of e- # of n 9 Atomic # Mass # Sym. Notation

Isotopes • Atoms of the same element that have different masses. • Same number of protons • Different number of neutrons p n How do these two nuclei differ?

Isotopes Example Carbon has 3 naturally occurring isotopes 12 6 C __ neutrons 13 6 C __ neutrons 14 6 C __ neutrons

Isotope Notation Example: Carbon -- 12 Carbon -- 13 Carbon -- 14 6 C Carbon 12. 01 Name Mass # Which is the most common isotope of Carbon?

Average Atomic Mass • The weighted average of all naturally occurring isotopes of an element Example: Chlorine has 2 naturally occurring isotopes Chlorine - 35 = 75. 77% 17 Chlorine - 37 = 24. 23% Cl Chlorine 35. 45 Avg. Atomic Mass = (mass 1 x decimal of % 1) + (mass 2 x decimal of % 2) +…