When the enthalpy change of the reaction is positive, the reaction is exothermic.
Rmm of N20 = (14X2) + 16 = 44
Percentage by mass of Nitrogen in N20 = 28/44x100 = 63.64
66x0.6634 = 43.7844g of Nitrogen in 66g of N20
Moles = Mass/Mr = 43.7844/14 = 3.13 moles
Ca, they only have two valence electrons, in order to become more stable, they would like to lose all of them
<span>Answer: option 3) magnesioum reacts with an acid.
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<span>Justification:
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<span>1) Malleability, conduction of electricity, and boiling point are physical properties.
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<span>2) Maleability is the ability to be transformed into foil. It is just a change in form. So, it is a physical property.
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<span>3) The metals conduct electricity in virtue of the array of the atoms, which permtis the flow of the electrons, but it does not involve a chemical change, so it remains being a physical proerty.
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<span>4) Boling point is the temperature at which a substance passes from liquid state to gas state, which are just different forms of the same substance. So, it is other physical property.
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<span>5) Reaction with an acid is indeed a chemical transformation: the metal (magnessium) will form a chemical bond with some spieces of the acid to form a new compound. This is a chemical reaction in virtue of the chemcial properties of the substance (its ability to react with acids)</span>