Structure Of The Atom And The Period Table Flashcards
What did John Dalton say
He said the atom is a solid sphere made of different elements
What did J.J Thomson do
He came up with electrons and created the plum pudding model
What did Ernest Rutherford say
He conducted the gold foil experiment
What was the gold foil experiment
Firing positively charged alpha particles at a thin sheet of gold, they expected particles to pass through the sheet or slightly deflected at most but most passed through but some were completely deflected which made the plum pudding model wrong
What did rutherford come up with in result of the gold foil experiment
He came up with the theory of the nuclear atom - a tiny + nucleus surrounded by a cloud of - electrons
What did Neils Bohr do
He created a new model where electrons were in shells - electrons could only exist in fixed orbits or shells and each shell has a fixed energy
What did Dimitri Mendeleev do
Arranged the elements in the table based on their properties, similar chemical properties into columns and he left gaps for undiscovered elements he predidcted properties for
How is the periodic table arranged now
Elements are arranged in order of increasing atomic number, elements with similar chem properties are placed in the same vertical columns called groups
