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What is Effective Nuclear Charge?

Effective Nuclear Charge is the net positive nuclear charge experienced by a valence electron orbiting the positively charged nucleus in an atom. Effective nuclear charge is redcued by: -increased distance b...
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Answered by Joshua O. • Chemistry tutor
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What is the difference between an Atom and an Ion?

An atom has the same number of protons and electrons so an atom has no overall electric charge. If an atom loses or gains electrons it becomes an ion. An ion is either positive or negative because it has an ...
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Answered by Phoebe W. • Chemistry tutor
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A metal oxide has a relative formula mass (Mr ) of 81. The formula of this metal oxide is MO. Given that the relative atomic mass (Ar ) of oxygen is 16, what is the metal in the metal oxide?

The formula of the metal oxide is MO, which means there is only one oxygen atom bonded to the metal. The Mr of a compound is the sum of Ar of the elements that make up the compound. So, from this we can cons...
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Answered by Jack T. • Chemistry tutor
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Without a catalyst, an alkene will react with bromine while benzene will not. Why is this?

The pi-bonds in benzene are delocalised over the entire ring, while in an alkene the pi-bonds are only delocalised over two carbon atoms. This means that benzene has a lower charge denisity than an alkene so...
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Answered by Jack T. • Chemistry tutor
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Why are GORE-TEX type materials are waterproof and yet breathable?

The material is made up from nylon laminated with a PTFE / polyurethane membrane. The m embrane is too fragile on its own hence why it is combined with the nylon. T he h oles in membrane are too small for wa...
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Answered by Lily B. • Chemistry tutor
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