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.
When discussing atoms, many people use atomic weight and atomic mass interchangeably, even though they aren't quite the same thing either. Atomic mass is defined as the number of protons and neutrons in an atom, where each proton and neutron has a mass of approximately 1 amu (1.0073 and 1.0087, respectively). The electrons within an atom are so miniscule compared to protons and neutrons that their mass is negligible.