Measurements and density

Today, Mr. Lim wrapped up the topic on Measurements and Units. He also went through the class assignment on IVLE with us. At the end, he gave us two questions to think about. The first was: There is a beaker of liquid with a density of A grams/cubic cm. A represents any natural number. There is also a solid that cannot be dissolved at the exact same density. Where in the beaker of liquid will it be? At the surface, in the liquid or at the bottom of the beaker?

In my opinion, this question is no practical as no two substances are identical. Each substance is unique and hence no two substances have the same density. Even ice and water, different states of the same substance, have different densitieas ice is less dense than water. Hence, this is not likely to happen.

However, in the event that it does happen by a stroke of luck... If it were a liquid, both liquids would mix together and form a mixture. However, since it is a solid, perhaps it would be in the liquid itself as that is the closest it gets to mxing. Also, to float would mean it is less dense and to sink would mean it is denser, so it would probably be in between.

The second question is as follows: Water always has a meniscus at the suface where it curves instead of being fully straight. Why? Even Mr. Lim is not too sure but he says it has something to do with surface tension. I think it is because air is pressing against the surface of water, causing it to bend and curve slightly. I shall research more on this subject when I have time.