Rutherford's alpha scattering experiment is used to demonstrate the structure of atoms. Beams of alpha particles, nuclei of helium atoms, are used to irradiate a gold foil. Rutherford observed a few alpha particles going straight through, a few small deflections, a few large deflections and a few particles scattered back, which indicates that an atom has an intensely positively charged nucleus at its center.Continue Reading
The alpha particles are produced by radioactive nuclides and are made to hit a gold foil a few atoms deep at a fixed angle in a vacuum. A zinc-sulfide-coated microscope lens attached to a turntable detects the deflected alpha particles at various angles. The lens at zero angle detects a higher number of scintillations per minute, while it detects lower rates at larger angles.
The results of Rutherford's experiments were mathematically evaluated, and the conclusion is that the particles that went straight through indicate the presence of an empty space in an atom. Particles that were less deflected were far away from the nucleus, and those that were more deflected were nearer to the nucleus. The particles that hit the positively charged nucleus were scattered back. Rutherford's new atomic model was accepted over the plum pudding model.Learn more about Particle Physics
Nuclear energy forms when atoms of uranium are split in a nuclear reactor through a process called fission. Small, hard ceramic particles containing uranium fuel are inserted into the reactor to produce steam, which turns the turbines in the reactor to produce electricity.Full Answer >
The modern atomic theory is a theory that all matter is composed of tiny particles called atoms. This theory is used in physics and chemistry to explain the behavior of all matter.Full Answer >
Brownian motion is caused by the impact of fluid molecules or atoms in rapid and random motion from heat on small particles suspended in the fluid. Brownian motion, which tends to disperse particles as widely as possible, is the major force in diffusion. Brownian motion occurs in small suspended particles, regardless of any overall movement or current in the suspending fluid.Full Answer >
The ionosphere is located between 46 and 621 miles above the Earth's surface and is composed of plasma, a state of matter that is a combination of free electrons and ionized atoms. The ionosphere contains the thermosphere and portions of the exosphere and the mesosphere.Full Answer >