It has been said that during the 20 th century, man harnessed the “power of the atom.” We made atomic bombs and generated electricity by nuclear power. We even split the atom into smaller pieces called subatomic particles. But what exactly is an atom? What is it made of? What does it look like? The pursuit of the structure of the atom has married many areas of chemistry and physics in perhaps one of the greatest contributions of modern science! . The parts of the atom: . chemistry and electromagnetism — -> electron (first subatomic particle).
radioactivity — -> nucleus. proton. neutron. How the atom is arranged – quantum mechanics puts it all together: . atomic spectra — -> Bohr model of the atom.
wave-particle duality — -> Quantum model of the atom WHAT DOES AN ATOM AND ITS PARTICLES WEIGH? An American Physicist named Robert Milian measured the electrical charge of an electron. With these two numbers (charge, charge to mass ratio), physicists calculated the mass of the electron as 9. 10 x 10-28 grams. For comparison: a U. S. penny has a mass of 2.
5 grams; so, 2. 7 x 1027 or 2. 7 billion billion billion electrons would weigh as much as a penny! Alpha particles – positively charged and massive. Ernest Rutherford showed that these particles were the nucleus of a helium atom. Beta particles – negatively charged and light (later shown to be electrons).
Gamma rays – neutrally charged and no mass (i.
The Essay on Central Atom Number Charge Anion
Hydrolysis of OxoanionsNonmetals in positive oxidation states do not exist in aqueous solution as cations but rather as hydroxides or oxides. These species often act as ox o acids which ionize to form in solution. The general form of an is MOxy-. Since these are quite different in their properties, Z 2/r ratios for nonmetal cations do not give accurate predictions of their chemical behavior. A ...
e. , energy).
When Rutherford bombarded nitrogen with alpha particles, a positively charged particle that was lighter than the alpha particle was emitted. He called these particles protons and realized that they were a fundamental particle in the nucleus. Protons have a mass of 1.
673 x 10-24 grams, about 1, 835 times larger than an electron! It was James Chadwick, a British physicist and co-worker of Rutherford, who discovered the third subatomic particle, the neutron. Chadwick bombarded beryllium foil with alpha particles and noticed a neutral radiation coming out. This neutral radiation could in turn knock protons out of the nuclei of other substances. Chadwick concluded that this radiation was a stream of neutrally charged particles with about the same mass as a proton; the neutron has a mass of 1.
675 x 10-24 grams.
