Using hydrogen in his experiments Bohr showed that an electron spins around the atom nuclei at a specific/discrete radii (orbital levels). Electrons at every orbital level spin at a discrete angular momentum and energy. When the electron moves one orbital level down, it releases a photon of energy specific to the jump (that is, of a particular spectrum that is unique to the atom). When the electron goes up an orbital level, energy (of a specific spectrum) is absorbed. This emission and absorption spectrum varies across atoms and is calculated as (delta)E = hf where;
E = energy
h = Planck's constant
f = frequency
Answer:
The correct answer is A. Fossil fuels are cheaper than alternative forms of energy
Explanation:
Fossil fuels are made from organic matter of dead animals and mainly plants who were buried in the soil over hundred and thousand of years. We use fossil fuels because they are the best source to provide energy in the current time.
Fossil fuels are easily available and are present in very large amount which is the main reason for it to be cheaper. Fossil fuels like coal, petroleum or natural gas are more cheaper and efficient than alternative forms of energy like solar or wind energy.
But in future these fossil fuel will not be there and alternative forms of energy will become the primary and cheaper source of fuel.
<span>In 2005, 27.99 males out of every 100,000 were diagnosed with melanoma.</span>
