Atomic Theory

The nucleus is very small and the atom is mostly empty space.

In the famous experiment conducted by Ernest Rutherford, positively charges alpha particles were scattered by a thin gold foil. What conclusion came from this experiment?

1) The atom consists of mostly empty space 2) Most of the MASS of an atom is located in its nucleus 3) The nucleus is POSITIVELY charged

What conclusions came from Rutherford's experiment?

Most alpha particles in Rutherford's experiment passed straight through a sheet of gold foil without being deflected.

What discovery indicated that atoms are mostly empty space?

The atom has a small but very dense nucleus containing protons surrounded by random electrons.

What model best describes the atom based on Rutherford's Gold Foil experiment?

The particles of the ray were SMALLER than atoms and were NEGATIVELY charged.

What was the main conclusion of J.J. Thomson's Cathode Ray Tube experiment. Later called electrons

All elements are made up of tiny indivisible and indestructable particles called atoms.

Which part of Dalton's Atomic Theory is no longer true based on modern understanding of atoms?

Atoms are indivisible and indestructible.

Which part of Dalton's Atomic Theory was disproven by the discovery of the Electron?

Currently accepted model of the atom: Cloud Model

1) Atoms have a small, dense, positively charges nucleus. 2) Protons and neutrons are found in the nucleus. 3) Most of the atom's mass is found in the nucleus. 4) Electrons exist in various shaped orbitals in a cloud around the nucleus