For the Focusâ first four model years, a 2.0-liter four-cylinder engine was offered and paired with a five-speed manual or a four-speed automatic transmission. Beginning in 2004, a 2.3-liter four-cylinder was also offered. In 2005, Ford refreshed the Focus shuffling trim and equipment offerings with it.
atomic mass - (chemistry) the mass of an atom of a chemical element expressed in atomic mass units. atomic weight, relative atomic mass. mass - the property of a body that causes it to have weight in a gravitational field. combining weight, eq, equivalent weight, equivalent - the atomic weight of an element that has the same combining capacity as a given weight of another element; the standard is 8 for oxygen.
According to HowStuffWorks, an atomic mass unit is defined as the mass of a single proton or neutron. Hydrogen, the lightest element, has an average mass of 1.00794 amu. A carbon-12 atom is made up of six protons and six neutrons, hence 12 atomic mass units. The mass of the electron is considered negligible, therefore electrons are not counted in measuring an atom's atomic mass.