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.
Atomic mass is the sum of the masses of the protons, neutrons, and electrons in an atom, or the average mass, in a group of atoms. However, electrons have so much less mass than protons and neutrons that they don't factor into the calculation. So, the atomic mass is the sum of the masses of protons and neutrons.