1.11 - Structure of the atom and isotopes Flashcards
Who discovered the electron?
J.J. Thomson
Who discovered the proton?
Ernest Rutherford
Who discovered the neutron?
James Chadwick
What are nucleons?
Protons and Neutrons
Where are electrons found?
In energy levels that surround the nucleus at fixed distances
What is the symbol, relative mass and relative charge for a proton?
p, 1, +1
What is the symbol, relative mass and relative charge for a neutron?
n, 1, 0
What is the symbol, relative mass and relative charge for an electron?
e-, 1/1840, -1
Other than discovering the proton, what is Rutherford credited for?
Discovering that the atom has a very small core, which contains the bulk of the mass of the atom.
What are energy levels also called?
Quantum shells
What is the atomic number of an element?
The number of protons in the atom
What is the mass number of an element?
The combined amount of protons and neutrons present in an atom
What is the mass number also called?
The nucleon number
What are isotopes?
Atoms of the same element with different masses
Why can’t isotopes of the same element have differing atomic numbers?
Because the atomic number is the number of protons in an element, and the number of protons is what determines what element an atom is
