Answer:
1. 
2. 
Explanation:
Hello,
1. In this case, since the volume of the rock is obtained via the difference between the volume of the cylinder with the water and the rock and the volume of the cylinder with the water only:

Thus, the density turns out:

2. In this case, given the density and mass of aluminum we can compute its volume as follows:

Moreover, as the volume is also defined in terms of width, height and length:

The height is computed to be:

Best regards.
<span>A </span>chemical formula<span> is a way of expressing information about the proportions of </span>atoms<span> that constitute a particular</span>chemical compound<span>, using a single line of </span>chemical element<span> symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and </span>plus<span> (+) and </span>minus<span> (−) signs. A chemical formula is not a </span>chemical name showing how the atoms are arranged.
??????????????????????????????????????????????
Color change bubbles and i think dissolving