Determine the number of protons, neutrons, and electrons in an atom of the isotope Iron-56 ($\text{}^{56}_{26}\text{Fe}$), and calculate its approximate mass in atomic mass units (amu).

Copper used in electrical wiring consists of two main isotopes: $\text{}^{63}\text{Cu}$ (mass $= 62.93 \, \text{amu}$, abundance $= 69.15\%$) and $\text{}^{65}\text{Cu}$ (mass $= 64.93 \, \text{amu}$, abundance $= 30.85\%$). Calculate the average atomic weight of copper.

An engineer must select a highly reactive metal for a sacrificial anode to protect a steel pipeline from corrosion. The choices are Magnesium (Mg) or Beryllium (Be). Based on periodic trends, which should be selected?

In Tungsten Inert Gas (TIG) welding, a shielding gas is required to protect the molten weld pool from atmospheric contamination (oxygen and nitrogen). Argon (Ar) is commonly used. Explain this choice based on atomic structure.

Compare the fundamental atomic bonding in a diamond cutting blade tip versus a sodium chloride (salt) de-icing agent. How do these bonds explain their physical properties?

Why can steel be rolled into I-beams (malleable/ductile) while concrete or ceramics would crack under the same stress? Explain using the electron sea model of metallic bonding.

Use VSEPR (Valence Shell Electron Pair Repulsion) theory to determine the geometry of a water molecule ($H_2O$) and explain why it is polar. This polarity is crucial for water's role as a universal solvent in concrete mixing.

Determine the geometry of $CO_2$ and its polarity. Contrast its behavior with water.