Your doctor may need to change the doses of your medications or monitor you carefully for side effects. ... Metformin side effects can also affect other parts of the body. It can leave a metallic taste in the mouth, cause heartburn or headache, flushing of the skin, nail changes or muscle pain. More serious metformin side effects include chest pain or rash. ...
Early String Theory. The first attempt to construct a physical model of an atom was made by William Thomson (later elevated to Lord Kelvin) in 1867. The most striking property of the atom was its permanence.
Ernst Rutherford (1871-1937) proposed the nuclear atom as the result of the gold-foil experiment in 1911. Rutherford proposed that all of the positive charge and all of the mass of the atom occupied a small volume at the center of the atom and that most of the volume of the atom was empty space occupied by the electrons.