This is because oxygen (2.8.6) requires two electrons on its valence shell to attain stable configuration (2.8.8). Hydrogen (1) on the other hand requires one electron on its valence shell to attain stable configuration (2). Therefore in a covalent bond, it requires two hydrogen and one oxygen to share electrons and achieve stable configuration.
Elements have neutral charges such as Na so if X has 72 protons + charges then it must also have 72 electrons with - charges
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1. <span>Substances in a </span>mixture<span> can be separated using different </span>methods, for example <span>distillation (separation of two liquids).
2. </span>Mass<span> is the amount of matter an object contains.
</span>Volume is t<span>he amount of space occupied by a three-dimensional object.
3. d(wallet) = 15g</span>÷5cm³ = 3g/cm³.
4. Weight of an astronaut also increases. W=m·g.
Answer:

Explanation:
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In this case, according to the given information it turns out possible for us to realize that one mole of the given compound, Mg(ClO₄)₂, has one mole of Mg, two moles of Cl and eight moles of O; thus, we proceed as follows:

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If the difference in electronegativtiy for the atoms in a bond are greater than 0.4,we consider the bond polar, if the electronegativity is less than 0.4, we consider it non polar. if there are no polar bonds, the molecule is non polar.