1 He 2  ... spectrum-spectrum spectrum, arrangement or display of light or other form of radiation separated according 3  ... atomic mass-atomic mass atomic mass, the mass of a single atom, usually expressed in atomic mass units (amu). ...he radius of this path depends upon the mass of the particles (all other factors, such as velocity and charge, being equal). Thus, if in the original stream isotopes of various masses are present, the position of the blackened spots on the plate makes possible a calculation of the isotope masses.
Almost all electrical appliances come for a standard voltage. Depending where you live, this is usually about 110 volts in some areas, and about 220 volts in other areas. You can take a look at a specific appliance; there is usually a metallic sticker that has the electrical specifications.
Household Wiring. The standard U.S. household wiring design has two 120 volt hot wires and a neutral which is at ground potential. The two 120 volt wires are obtained by grounding the centertap of the transformer supplying the house so that when one hot wire is swinging positive with respect to ground, the other is swinging negative. This versatile design allows the use of either hot wire to supply the standard 120 volt household circuits.