Question

sodium chloride
nacl

calcium chloride
cacl₂

strontium nitrate
(sr(no₃)₂)

1. draw the bohr model for ba²⁺

Explanation:

Step1: Determine atomic number of Ba

Barium (Ba) has an atomic number of 56, so a neutral Ba atom has 56 protons and 56 electrons.

Step2: Account for charge of Ba²⁺

Ba²⁺ means it has lost 2 electrons, so the number of electrons is \( 56 - 2 = 54 \).

Step3: Determine electron shell configuration

The electron shell filling follows the rules: 2 (first shell), 8 (second), 8 (third), 18 (fourth), 18 (fifth), and the remaining in the sixth (but for Ba²⁺, after losing 2, the electron configuration is like Xenon (Xe), which has a stable noble gas configuration with electron shells: 2, 8, 18, 18, 8.

Step4: Draw the Bohr model

• Nucleus: Contains 56 protons (and neutrons, but Bohr model focuses on electrons and nucleus with protons; number of neutrons can be calculated as mass number - atomic number, but for drawing, we can represent the nucleus with 56+ (protons) and neutrons (not labeled numerically usually, just as the nucleus).
• Electron shells:
• First shell (n=1): 2 electrons.
• Second shell (n=2): 8 electrons.
• Third shell (n=3): 18 electrons.
• Fourth shell (n=4): 18 electrons.
• Fifth shell (n=5): 8 electrons.
• Sixth shell: 0 electrons (since it lost 2, the valence shell (sixth) now has 0, and the fifth shell is the outermost with 8, making it isoelectronic with Xe).

To draw:

1. Draw a small circle for the nucleus, label it with "56+" (representing protons).
2. Draw concentric circles (electron shells) around the nucleus.
3. On the first shell, place 2 dots (electrons).
4. On the second shell, place 8 dots.
5. On the third shell, place 18 dots.
6. On the fourth shell, place 18 dots.
7. On the fifth shell, place 8 dots.
8. The sixth shell has no electrons (so no dots, or you can omit drawing the sixth shell as it's empty).

Answer:

The Bohr model of \( \text{Ba}^{2+} \) has a nucleus with 56 protons, and electron shells with 2, 8, 18, 18, 8 electrons (from inner to outer shells, with the sixth shell empty). The visual representation includes a nucleus labeled \( 56^+ \) and concentric circles (shells) with the respective number of electron dots on each shell.