Magnesium is burned in air in an open crucible and the mass of the solid increases. Which explanation is correct?

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Question

Magnesium is burned in air in an open crucible and the mass of the solid increases. Which explanation is correct?

Accepted Answer

Oxygen from the air has combined with the magnesium and is included in the product — Award 1 mark. Conservation of mass still holds once the oxygen taken from the air is counted as a reactant, which is why an apparent gain and an apparent loss have the same underlying explanation.

Answer

Mass has been created during the reaction

Answer

Oxygen from the air has combined with the magnesium and is included in the product

Answer

The balance reads high when hot

Answer

The magnesium has absorbed heat energy, which has mass

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