The answer would be D. The only minerals harder than corundum is diamond.
If there are 2 electrons in the same orbital, the spin numbers would be different for both of these 2 electrons. One would have an up spin and the other a down spin.
Symbol "X" represents Nitrogen, phosphorus, and arsenic.as they have five valence electrons in their valance shell.
<h3>What is a Lewis notation?</h3>
A Lewis form is a completely simplified illustration of the valence shell electrons in a molecule. it's miles used to expose how the electrons are organized round man or woman atoms in a molecule. Electrons are proven as dots or for bonding electrons as a line between the 2 atoms.
Lewis systems, also known as electron-dot structures or electron-dot diagrams, are diagrams that show the bonding between atoms of a molecule, and the lone pairs of electrons that can exist within the molecule.A Lewis form is based totally at the idea of the octet rule, wherein atoms percentage electrons in order that every atom has 8 electrons in its outer shell. for example, an oxygen atom has six electrons in its outer shell.
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Weathering is the process of breaking large rocks and boulders into much smaller ones. Weathering can be brought about by wind and water mostly. Sometimes even biological forces account for some types of weathering.
Answer:
Chemical reactions that absorb (or use) energy overall are called endothermic. In endothermic reactions, more energy is absorbed when the bonds in the reactants are broken than is released when new bonds are formed in the products.