Wilhelm Conrad Roentgen was a German scientist who discovered x-rays through the use of Crookes tube, a tube he used in studying cathode rays that emitted new kinds of invisible ray that was capable of penetrating through a black paper.
After hearing such discovery, Henri Becquerel, a French scientist had also took interest in the connection between the phosphoresence he had already been investigating and the newly discovered rays. He thought that the phosphoresence uranium salts he had been observing and studying might absorb sunlight and emit it as x-rays.
To test such idea which was disproved later on, Becquerel wrapped photographic plates in black paper so that sunlight could not reach them. He then placed the crystals of uranium on top of the wrapped plates and put the whole set up outside, exposed under the sun.
When he developed the plates, he saw an outline of the uranium crystals. He also placed other objects such as coins or cut out metals between the crystals and the photographic film/plate. It also turned out that he could also produced outlines of those shapes.
B vitamins play a vital role in maintaining good health and well-being. As the building blocks of a healthy body, B vitamins have a direct impact on your energy levels, brain function, and cell metabolism.
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The most chemically stable of the four atoms given the <em>electron configuration</em> of each is; Choice A : He.
Helium (He) is a chemical element with the atomic number 2 on the periodic table. It's electron formation is 1s². It has zero valence electron in it's atomic shell.
Lithium (Li) is a chemical element with the atomic number 3 on the periodic table. It's electron formation is 1s² 2s¹. It has 1 valence electron in it's atomic shell.
Nitrogen (N) is a chemical element with the atomic number is 7 on the periodic table. It's electron formation is 1s² 2s² 2p³. It has 3 valence electron in it's atomic shell.
Sulphur (S) is a chemical element with the atomic number is 16 on the periodic table. It's electron formation is 1s² 2s² 2p⁶ 3s² 3p4. It has 4 valence electron in it's atomic shell.
Chemical stability is measured by the number of valence electron present in a chemical element atomic shell. Therefore Helium (He) has zero (0) valence electron in it's atomic shell making it the most stable amongst the chemical element listed above because elements with zero valence electron are unreactive and are the most stable elements on the periodic table.
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The answer is A.combustion
Overproduction of offspring
