1. Particles of an Atom You know, like particle-things and such…

2. Subatomic Particles ParticleLocationMassCharge Electron“Clouds” around nucleus – We don’t know exactly Almost zeroNegative ProtonNucleus1 amuPositive NeutronNucleus1 amuNeutral

3. Mass of Subatomic Particles

4. Size of Nucleus

5. Atomic Number A number unique to each element. Represents the number of protons in an atom. Also represents the number of electrons

6. Mass Number Represents the mass of an atom. Represented in “Atomic Mass Units” (amu) Mass # = # of protons + # of neutrons

7. Equations Atomic # = # of protons = # of electrons Mass # = # of protons + # of neutrons

8. SymbolElementAtomic #ProtonsNeutronsElectronsMass # Carbon612 Zn36 614 Einsteinium252 80120 Cu64 Gold130 Lu175 74184

9. Isotopes Atoms of the same element with different mass numbers. Mass # Atomic # Nuclear symbol: Hyphen notation: carbon-12

10. Isotopes + + + + + + Nucleus Electrons Nucleus Neutron Proton Carbon-12 Neutrons 6 Protons 6 Electrons6 Nucleus Electrons Carbon-14 Neutrons 8 Protons 6 Electrons6 + + + + + + Nucleus Neutron Proton

11. Isotopes Chlorine-37 –atomic #: –mass #: –# of protons: –# of electrons: –# of neutrons: 17 37 17 20 Cl 37 17