Unit 1: Structure of an Atom Flashcards
Mass number
Number of protons and neutrons in an element, technically not found on the periodic table because it’s an average
Atomic mass
The weighted average of all the isotopes of an element
Atomic number
Number of protons in an atom
Isotopic notation
Mass number
(Element Abbreviation)
Atomic number
Name and number method
Element name- mass number
Determine composition of an element
Mass number-atomic number= number of neutrons
What does it mean when the element has more electrons than protons
Negatively charged
What does it mean when the atom has more protons than electrons
Positively charged
Isotopes
Variation of an element with a different number of neutrons
Ernest Rutherford
Major Contributions: the nucleus, atoms are mostly empty space
Golf foil experiment
Gold foil experiment
Done by earnest Rutherford
Shot alpha particles at gold foil
Most particles went through but some bounced back randomly
Five Principles of ______’s atomic theory
John Dalton’s theory
1) Atoms of different elements are different
2) Atoms of the same element are the same
3) Compounds can be created when two or more elements chemically combine in whole number rations
4) During chemical changes, atoms can be separated or combined but not created or destroyed
5) Atoms are indivisible and make up everything
Who discovered the electron
JJ Thompson
Who created the Plum Pudding model
JJ Thompson
Plum Pudding Model
Had electrons and protons but nothing had a specific place
