Oregon. A state of the northwest United States in the Pacific Northwest. It was admitted as the 33rd state in 1859. Claimed by the United States after Capt. Robert Gray explored the mouth of the Columbia River in 1792, the area was further explored by Lewis and Clark in 1805 and was soon the site of fur-trading posts.
The unified atomic mass unit (u) or Dalton ( Da) is a unit that is used for indicating mass on an atomic or molecular scale. One Da is approximately equal to the mass of one proton or one neutron. An atomic mass unit or amu is one twelfth of the mass of an unbound atom of carbon-12. This means that a carbon-12 atom has the atomic mass of 12 daltons. Mass is the property which reflects the quantity of matter within a sample.
The number of electrons is the same as the number of protons in the nucleus. atomic mass (sometimes mistakenly called atomic weight): The mass of a neutral atom. Its value in atomic mass units (u) is approximately equal to the sum of the number of protons and neutrons in the nucleus of the atom.