5. an aluminum (aℓ) cylinder is 10.0 cm in length and has a radius of 2.5 mm. if the mass of a single aℓ atom is 4.48 x 10-23 g, calculate the number of aℓ atoms present in the cylinder. the density of aluminum is 2.70 g/cm3. (volume of a cylinder = π r2 ℓ and π=3.14)

= 1.183 × 10^25 atoms

Volume of  a cylinder is given by the formula;

πr²h , where r is the radius, and h is the height or length.

Volume = 3.14 × 2.5² × 10

             = 196.25  cm³

But density = 2.7 g/cm³

Therefore;

Mass = volume × density

        = 196.25 × 2.7

        = 529.875 g

But; 1 atom =  4.48 x 10-23 g

Therefore;

Number of atoms = 529.875 g / 4.48 x 10-23 g

                              = 1.183 × 10^25 atoms

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.