A spiracle ball of lead has a diameter of 3.5 cm. What is the mass of the sphere if lead has a density of 11.34 g

741.8 kg

Explanation:

mass =  volume  x   density

volume = πr²

   since Diameter = 3.5 cm

   then   radius = 1.75cm

∴ volume  =  π  x  (1.75cm)³

                ≈  16.8369731 cm³

Thus mass  =  16.8369731 cm³  x  11.34  g / cm³

                   =  190.93 g

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)