<span>At higher altitudes (and thus lower atmospheric pressures), water boils at a lower temperature. This is because the lack of vapor pressure at that altitude doesn't constrain the speed of the molecules with barometric pressure. Therefore, the water begins boiling at a lower temperature. This is often a disadvantage because even if the water is boiling, it won't be hot enough for meals (which is why heat and temperature are distinct). That's why we have pressure cookers, which manage to keep a stable boiling point.
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Answer: A. the variable that is changed on purpose in an experiment.
It's B. Since density equals mass/volume. The missing quantity needed is mass.Hope this helps.
<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>