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.
51.86 grams would be in the container.
One ounce is an equivalent of 28.34 grams, so times that by 12.2
.
12.2 * 28.34 = 345.75.
Put the percentage into decimal form, so 15% would now be 0.15.
0.15 * 345.75 = 51.86.
Answer: We do not know. We have not been given the solubility of oxygen in water at a given temperature nor have we been given the Henry's laws constant. We also do not know whether you mean 1 atmosphere of air, or 1 atmosphere of oxygen.
The answer should be A. CaO + CO2 —> CaCO3
The time taken for the same volume of methane gas to diffuse is 7.1 s.
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Rate of gas diffusion</h3>
The rate at which a given mass of diffuses is inversely proportional to the molar mass of the gas.

where;
- M1 is the molar mass of methane (CH4) = 16 g
- M2 is the molar mass of hydrogen as = 2
- t1 is time taken for methane = 20 s
- t2 is the time taken for hydrogen = ?

Thus, the time taken for the same volume of methane gas to diffuse is 7.1 s.
Learn more about rate of gas diffusion here: brainly.com/question/26696466