During an investigation a scientist burned 48 g of magnesium strip. after the reaction the total mass of the product formed was found to be 80 g. does the law of conservation of mass hold true in this case? use complete sentences to justify your answer based on numerical calculations.

The law of conservation of mass applies to both cases

      When 50 g of sugar undergoes a physical change, say for example  melting, the amount of sugar in the solution or melted form will also be 50 grams. This shows that the mass before and after the change was the same, in accordance to the law of conservation of mass. The mass stays the same.

When the magnesium strip is burned, this is a chemical reaction. The problem is that we only measure the mass of one of the substances involved in the reaction which is the magnesium strip, which makes it seem like the mass has increased. Actually, while burning, the magnesium combines with oxygen in the air. This oxygen was present before the reaction, we just did not measure it. And after the reaction it is present in the form of product. But the mass is still conserved.

Hope this helps!!:)

Explanation:

yes, the law of conservation of mass hold true in this case

burning magnesium strip is explained by this equation

2 Mg (s) + O2 (g) -> MgO (s)

So the lighter magnesium, after reacting with oxygen in air, forms the heavier magnesium oxide. molar mass of magnesium and magnesium oxide are 24g and 40g respectively. So the same ratio 24:40 (i.e. 3:5) is maintained in the given masses of 48g and 80g, which means mass is conserved in the reaction.

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.