Chemistry homework help pleaseee!!!!

Body composition refers to the percentage of a person's body mass that is composed of lean tissue or fatty tissue. Lean tissue, which includes muscle and bone, is more dense than water. Fatty tissue is less dense than water. Would you expect a person who has 30 percent body fat to float higher or lower in the water than a person of the same mass who has 10 percent body fat? Explain.


2. Modern jet airplanes are built primarily out of aluminum and another metal, titanium, which has a density of 4.5 g/mL. Why do you think these metals are preferred over the other metals, such as iron and lead?


3. Many metallic materials are alloys, or mixtures of two or more metals. For example, brass is an allow of copper and zinc. How would you expect the density of brass to compare to the density of pure copper? Explain



Pleaseee help!! I'm having trouble :(

1. The fatter person floats.
(30% floats closer to the surface than 10%)

2. Lead weighs 207.2 g/mol.
Iron weighs 55.874 g/mol.
Aluminum 28.98 g/mol
Titanium 47.867 g/mol

Aluminum is lightweight. Titanium isn't very dense and is resistant to corrosion. This is very important when you think about the exposure to water.

3. The Density of copper is 8.94 gm/cm^-3
Brass alloys typically have densities in the range of 8.4 to 8.75 gm/cm^3