Rutherford's scattering experiment showed that atoms consist mostly of empty space, with a positively charged nucleus at the center. His experiments provided the first working model of atomic structure based on observation. Rutherford’s atom has a planetary structure, with negatively charged electrons orbiting around a positively charged nucleus and a large amount of empty space between the two.Know More
Atomic models remained mostly speculative until 1911 when Ernest Rutherford proposed his model using experimental data from scattering experiments conducted by Hans Geiger and Ernest Marsden under Rutherford’s direction. The experiment used alpha particles (helium ions) directed toward a thin gold foil target. They observed that most of the positively charged alpha particles passed straight through the foil. Some of the alpha particles showed small deflections of just a few degrees as they passed through, but a few showed a large deflection angle, greater than 90 degrees. Based on these results Rutherford proposed that atoms contain a small, densely packed nucleus with a positive charge and that electrons, considerably smaller, orbited the nucleus.
Based on Rutherford’s equations, physicists had their first solid evidence of the size of the nucleus relative to the size of an atom itself. Subsequent experiments would refine these numbers. Neils Bohr refined Rutherford’s planetary model and countered objections to the orbiting electrons by creating energy shells and describing how energy moved from one shell to another and emitted light quanta to maintain a balance. While quantum physics explains the energy states more accurately, Rutherford’s nucleus still persists, albeit in a wildly different way than he might have imagined.Learn more about Physics
There are many physics jokes, such as the atoms and electron anecdote. Two atoms bump into each other. One says, "I have lost an electron!" The other asks, "Are you sure?" The first replies, "Yes, I'm positive."Full Answer >
Heat energy is determined by how active the atoms or molecules are in a substance. The atoms and molecules in a hot substance move rapidly and seem excited while the molecules and atoms in a cool substance show less movement.Full Answer >
Although both atomic and nuclear bombs derive their immense power from reactions that take place in the nucleus of the atom, they do so in different ways. As the terms are most commonly used, an atomic bomb derives its energy from fission, or splitting atoms, while a nuclear device, or "H-bomb," is driven by fusion.Full Answer >
Nuclear binding energy is the amount of energy that is needed to split a nucleus into many different parts. The split parts are composed of neutrons and protons, and collectively, all the parts are known as nucleons.Full Answer >