An early model of the atom was developed in 1913 by Danish scientist Niels Bohr (1885–1962). The Bohr model shows the atom as a central nucleus containing protons and neutrons with the electrons in circular orbitals at specific distances from the nucleus . These orbits form electron shells or energy levels, which are a way of visualizing the number of electrons in the various shells. These energy levels are designated by a number and the symbol "n." For example, 1n represents the first energy level located closest to the nucleus.
Answer:
D.
Explanation:
Deciding whether the best product has been designed,should be the last step.
1 gal ---------- 3785.41 cm³
2.9 gal --------- ??
2.9 x 3785.41 / 1 => 10977.689 cm³
The average atomic weight is calculated by adding up the products of the percentage abundance and atomic weight. In this item, we have the equation,
A = (0.412)(21.016 amu) + (0.5012)(21.942 amu) + (0.0868)(23.974 amu)
Simplifying the operation will give us the answer of 21.74 amu.
<em>Answer: 21.74 amu</em>