Questions: Which of the following correctly represent the placement of electrons around each atom? Drag each item to the appropriate bin. [: Br:]^- Ca^2+[: Br:]^- Na: F: Na^-[: F]^+ [: Br:]^+ Ca^2-[: Br:]^+

Solution Steps

To determine the correct placement of electrons around each atom, we need to analyze the electron configurations and charges of the given species.

1. $[: \ddot{\mathrm{Br}}:]^{-} \mathrm{Ca}^{2+}[: \ddot{\mathrm{Br}}:]^{-}$:

   • Bromine ions ($\mathrm{Br}^-$) typically have a full octet with an extra electron, making them negatively charged. Calcium ions ($\mathrm{Ca}^{2+}$) lose two electrons, resulting in a positive charge. This configuration is valid as it represents a typical ionic compound with correct charges.

2. $\mathrm{Na}: \stackrel{:}{\mathrm{F}}:$:

   • Sodium (Na) typically loses one electron to form $\mathrm{Na}^+$, and fluorine (F) gains one electron to form $\mathrm{F}^-$. This configuration is valid as it represents a typical ionic bond between sodium and fluorine.

3. $\mathrm{Na}^{-}[: \stackrel{\rightharpoonup}{\mathrm{F}}]^{+}$:

   • Sodium typically does not gain electrons to form $\mathrm{Na}^-$, and fluorine does not lose electrons to form $\mathrm{F}^+$. This configuration is invalid.

4. $[: \ddot{\mathrm{Br}}:]^{+} \mathrm{Ca}^{2-}[: \ddot{\mathrm{Br}}:]^{+}$:

   • Bromine typically does not lose electrons to form $\mathrm{Br}^+$, and calcium does not gain electrons to form $\mathrm{Ca}^{2-}$. This configuration is invalid.

Based on the analysis, we categorize each option as valid or invalid:

• Valid:

  • $[: \ddot{\mathrm{Br}}:]^{-} \mathrm{Ca}^{2+}[: \ddot{\mathrm{Br}}:]^{-}$
  • $\mathrm{Na}: \stackrel{:}{\mathrm{F}}:$

• Invalid:

  • $\mathrm{Na}^{-}[: \stackrel{\rightharpoonup}{\mathrm{F}}]^{+}$
  • $[: \ddot{\mathrm{Br}}:]^{+} \mathrm{Ca}^{2-}[: \ddot{\mathrm{Br}}:]^{+}$

Final Answer