atomic models
modelos atómicos
What is an atom?
Bohr Model
electrons "orbit" the nucleus like planets orbit the sun
Modern Atomic Model
Modelo atómico moderno
electrons are a "cloud" around the nucleus
the first shell can hold a maximum of two electrons.
the second and third shells can each hold eight.
valence electrons
the electrons in an atom's outer-most shell
mass number and atomic number
atomic number = number of protons
mass number = number of protons and neutrons
