<span>If you give it a good search, the most used answer would probably be as follows,
</span><span>In 1914 Henry Moseley found a relationship between an element's X-ray wavelength and its atomic number (Z), and therefore rearranged the table by nuclear charge / atomic number rather than atomic weight. Before this discovery, atomic numbers were just sequential numbers based on an element's atomic weight. Moseley's discovery showed that atomic numbers had an experimentally measurable basis.
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Hope this helps!
I believe the answer is
At the moment it is the best way of explaining our scientific knowledge.
Answer: The frequency of the wave is 0.5 hertz.
Explanation:
= Frequency of the wave
= speed of the light in m/s
= Wavelength of the wave.
Here in question we are given with speed of the infrared light. So, we will replace the value of speed of light(c) from the given value of the speed of the infrared light.
Speed of infrared light = 6 m/s
The frequency of the wave is 0.5 hertz.
Mass = mr x moles
Mr of CuCl2 = ( 63.5) + ( 35.5 x 2) = 134.5
2.5 = 134.5 x moles
2.5 / 134.5 = moles
Moles = 0.019 (2DP)
0.25g of Al
Mr of Al = 27
0.25 = 27 x moles
0.25/ 27 = 0.0093 moles (2sf)
Hope this helps :)
John Dalton was a scientist who proposed that all matter consists of atoms. At this stage, no one had yet discovered neutrons and the nucleus. As a result, Dalton's model consisted of a single atom i.e. the atom was the smallest object.
A mass spectrometer is an instrument that is able to see what is inside an atom. Scientists have been able to prove that the item is not the smallest object in the world. Atoms are made up of smaller objects called protons, neutrons and electrons.
We can, therefore, safely conclude that data from mass spectrometry has helped modern scientists to make modifications to Dalton's model. <span>
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