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.
The atomic number is the number of protons â positively charged particles â in the nucleus an atom of a chemical element. Elements are distinguished from one another by the numbers of these particles they have, and so each element has its own unique atomic number.