Fundamental Concepts in Atomic Structure, Isotopes, and Chemical Compounds

A sample of copper metal has a mass of 5.00 g. The atomic radius of copper is approximately $1.28 \times 10^{-10}$ m. Assuming copper atoms are spherical and packed without empty space, estimate the number of copper atoms in the sample. (Molar mass of Cu = 63.55 g/mol, Avogadro's number $N_A = 6.022 \times 10^{23}$ mol$^{-1}$)

Given the isotope symbol $^{37}_{17}\mathrm{Cl}^-$, determine the number of protons, neutrons, and electrons in this ion.

Boron has two naturally occurring isotopes: $^{10}\mathrm{B}$ (mass = 10.0129 amu, abundance = 19.9%) and $^{11}\mathrm{B}$ (mass = 11.0093 amu, abundance = 80.1%). Calculate the atomic weight of boron.