The law of conservation of mass applies to both cases, the following will explain how:
1. When 50 g of sugar undergoes a physical change, say for example dissolving or 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.
2. 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, the magnesium strip, which makes it seem like the mass has increased. Actually, during 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. Therefore, mass is still conserved.
B
Explanation:
I rember when I learned this in 3rd grade
Answer:
Convection is the process of heat transfer in which hotter and therefore less dense matter floats to the top, while cooler and therefore more dense material sinks to the bottom to absorb heat.
Explanation:
Convection is one form of heat transfer; other forms include conduction and (heat) radiation (not exactly the same as the kind uranium emits).
This form of heat transfer is characterised by a use of current in a liquid, in which the sinking and rising create a current which has a shape of a loop.
This requires an outside source of heat, since to sustain the current, once the heated fluid rises up, it must lose heat to the environment to sink, but to rise it must gain heat again.
