Particle Symbol Relative Charge

Relative Mass (proton = 1)

Actual Mass (g)

Electron e- 1- 1/1840 9.11X10-28

Proton p+ 1+ 1 1.67x10-24

Neutron n0 0 1 1.67x10-24

Properties of Subatomic Particles

Subatomic ParticlesProtonPositively charged particle Equal to the Atomic Number

ElectronNegatively charged particleEqual to # of protons (in a neutral atom)

NeutronUncharged particle (neutral)Equal to Mass Number – Atomic Number

Location of Subatomic ParticlesProtons and neutrons are found in the nucleusElectrons located in energy levels (orbitals) outside of the nucleus

CCarbon

6

12.011

Atomic

Number

Element

Name

Chemical

Symbol

Atomic

Mass/Weight

Atomic NumberNumber of protons in atomNumber of electrons in atom

Mass Number (Atomic Mass rounded)Number of protons plus neutrons

Chemical SymbolOne or two letters that stand for the element

126C protons=6

electrons = 6 neutrons=6(12-6)

atomic number

mass number (rounded atomic mass)

Ions-atoms that have gained or lost electrons (negative particles)

Anion: atoms that have gained electrons and have a negative charge

Cation: atoms that have lost electrons and have a positive charge

Isotopes-Atoms that have the same number of protons, but different numbers of neutrons-different mass numbers

Neon-20 10 neutronsNeon-21 11 neutronsNeon-22 12 neutrons

(Average) Atomic Mass

-isotopes occur in nature in a certain percentage (percent natural abundance) -the atomic mass of an element is a weighted average mass of atoms occurring in nature-see table 4.3

Name Percent Abundance

Mass (amu) Average Atomic Mass

Carbon-12 98.89 12.00012.011

Carbon-13 1.11 13.003

Carbon-14 ≤.01 14.000

(.9889 * 12.000) + (0.0111 * 13.003) = 12.011