Atomic Concepts #1

Niels Bohr

• 1. Planetary Model

• 2. Solar System Model

• 3. Electron-Shell Model

• 4. Atomic Orbital Model

Average Atomic Mass

• The total mass of an element's isotopes

• The weighted average of all naturally occurring isotopes of an element

• The mass of the most abundant isotope

• The average mass of an element's atoms in a molecule

Most Abundant Isotope

• Isotope that makes up the largest percentage of atoms of an element

• Isotope with the highest atomic number

• Isotope that is least stable

• Isotope that has the lowest mass number

Atomic Number

• Identifies the element

• Number of neutrons in an atom

• Total mass of the atom

• Number of electrons in an atom

u

• atomic mass unit

• unit of energy

• unified atomic number

• universal constant

What is Ernest Rutherford known for?

• Gold-Foil Experiment

• Plum Pudding Model

• Quantum Theory

• Periodic Table of Elements

Neutron

• Located inside the nucleus

• Has a positive charge

• Located outside the nucleus

• Has a negative charge

Orbital

• Electron Cloud

• Nucleus

• Proton Shell

• Neutron Zone

Atom

• Electrically neutral

• Contains equal amounts of neutrons and electrons

• Contains more protons than electrons

• Always has a positive charge

Mass Number

• Mass Number = # Neutrons + # Protons

• Mass Number = # Protons - # Neutrons

• Mass Number = # Electrons + # Protons

• Mass Number = # Neutrons - # Protons