Ablock of aluminum occupies a volume of 15.0 ml and weighs 40.5 gallons what is the density

Hello!

I'm going to have to infer that you meant "grams" and not "gallons" :-)

Anyways, to find the density, you need to the divide mass over volume (d = m/V).

Since we are given the volume being 15.0 mL, and the weight being 40.5 grams, we can find the density of the aluminum block.

40.5 grams / 15.0 mL = 2.7 g/mL

Therefore, the density of the aluminum block is 2.7 grams per milliliter.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

fe 55.85 g/mol and h2o 18.02 g/mol.