The answer is d Thus, the first energy level holds 2 * 1^2 = 2 electrons, while the second holds 2 * 2^2 = 8 electrons. Each orbital. The third energy level can hold up to 18 electrons, meaning that it is not full when it has only electrons.
The molar mass of naphthalene is calculated as follows,
10 x (12.01 g/ mol) + 8 x (1.01 g/mol) = 128.12 g/mol
Divide the given mass by the molar mass to determine the number of moles of naphthalene present in the ball.
n = 1.52 g / 128.12 g/mol = 0.01186 mole
Multiply the number of moles to number of moles per mole.
(0.01186 mol) x (6.022 x10^23 molecules / mole) = 7.14 x 10^21 molecules
Let MM(x) be the molar mass of x.
MM(Pb) : MM(PbO)
=207.21 : 223.20 = 451.4 g : x g
cross multiply and solve for x
x=223.2/207.21*451.4
= 486.23 g
Percentage yield = 365.0/486.23= 0.75067 = 75.07% (rounded to 4 sign. fig.)
Magnesium is the correct answer
