History of the Periodic table Flashcards
how is the modern table arranged?
it shows elements in order of increasing atomic number
how were older versions of the periodic table arranged?
ordered by atomic mass of the element
What issue did Lavoisier’s table have?
the elements were not in order of atomic mass or number
what issue did Newlands’ table have?
elements in the same groups had very different properties
What was good about Mendeleev’s table?
he left gaps for undiscovered elements
How did Mendeleev predict the properties of undiscovered elements?
by working out the atomic mass he could predict their reactivity
What was J.J Thompson’s model for the electron called?
the plum pudding model
What did Ernest Rutherford find out?
atoms have a small central nucleus meaning the majority of the atom is empty space
What did Niels Bohr describe the atom as?
a tiny solar system, with the nucleus being the sun and the electrons the planets
