The mineral that is the hardest known substance in nature is a diamond.
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1) Molecular formula of ammonium sulfide
(NH4)2 S
2) That means that there are 2*4 = 8 atoms of hydrogen in each molecule of ammoium sulfide, so in 5.20 mol of molecules will be 8 * 5.20 mol = 41.6 moles of atoms of hydrogen
3) To pass to number of atoms multiply by Avogadro's number: 6.022 * 10^23
41.6 moles * 6.022 * 10^23 atoms / mol = 250.5 * 10^23 = 2.50 * 10^25 atoms
Answer: 2.50 * 10^25
In order to conduct the two-slit experiment with a beam of electrons, the slit opening has to be smaller than the opening for the light waves. This is because the wavelength of the electron beam is lower, which means it will pass through the large slit without diffracting. Diffraction will occur if the spacing is reduced. The reason that electrons have a smaller wavelength is because they have a higher energy than light waves.