As of 2013, the United States spends about $554.2 billion annually to fund its military forces, and appropriates approximately $88.5 billion to fund Overseas Contingency Operations. Put together, the United States constitutes roughly 39 percent of the world's military expenditures.
the number of protons in the nucleus of an atom of a particular element. In a neutral atom, the atomic number equals the number of electrons. See also atom, electron, proton.
1 The number of neutrons in an atom may be calculated from the atomic number of that atom (element) and the mass number of that atom (isotope). Number of Neutrons (in an atom) = Mass Number (A) - Atomic Number (Z)  Protons and neutrons are collectively referred to as nucleons.