Q1. The nucleus of an atom is given on the right as a circle. Use this to answer the following questions: I. Complete the table below.

Q1. The nucleus of an atom is given on the right as a circle. Use this to answer the following questions.

I. Complete the table below.

• Protons: The number of protons (p) is given as 11.
• Neutrons: The number of neutrons (n) is given as 12.
• Electrons: In a neutral atom, the number of electrons is equal to the number of protons. So, electrons = 11.
• Atomic number: The atomic number (Z) is equal to the number of protons. So, atomic number = 11.
• Atomic mass: The atomic mass (A) is the sum of protons and neutrons. So, atomic mass = 11 + 12 = 23.

$$\begin{array}{|c|c|c|c|c|} \hline \text{Protons} & \text{Neutrons} & \text{Electrons} & \text{Atomic number} & \text{Atomic mass} \\ \hline 11 & 12 & 11 & 11 & 23 \\ \hline \end{array}$$

II. Is it metal or non-metal? Specify and Name this atom.

The atom has 11 protons, which identifies it as Sodium (Na). Sodium is an alkali metal, located in Group 1 of the periodic table.
It is a metal.

III. Draw electron shell diagram for this atom, and also draw its valence shell diagram.

• Electron Shell Diagram (Bohr Model): Sodium has 11 electrons. The electron configuration by shells is 2, 8, 1. The diagram shows the nucleus with 11 protons and 12 neutrons, surrounded by electron shells.

  • First shell (K-shell): 2 electrons
  • Second shell (L-shell): 8 electrons
  • Third shell (M-shell): 1 electron

  (Diagram representation - imagine concentric circles)

  $$\text{Nucleus (11p, 12n)} \\ \text{1st shell (2 electrons)} \\ \text{2nd shell (8 electrons)} \\ \text{3rd shell (1 electron)}$$

• Valence Shell Diagram (Lewis Dot Structure): The valence shell is the outermost shell, which contains 1 electron for Sodium.

  $$\text{Na} \cdot$$

IV. Write the main shell electron configuration for this atom.

The main shell electron configuration (Bohr model) for Sodium (11 electrons) is:

$$\boxed{\text{2, 8, 1}}$$

V. Write the subshell electron configuration for this atom.

The subshell electron configuration for Sodium (11 electrons) follows the Aufbau principle:

$$\boxed{1s^2 2s^2 2p^6 3s^1}$$

VI. Write the condensed subshell electron configuration for this atom.

The noble gas preceding Sodium is Neon (Ne), which has the configuration $1s^2 2s^2 2p^6$.
The condensed subshell electron configuration for Sodium is:

$$\boxed{[Ne] 3s^1}$$

VII. Write and represent the ground state and excited state for this atom.

• Ground State: The ground state is the lowest energy electron configuration.

  $$\text{Configuration: } 1s^2 2s^2 2p^6 3s^1$$

  Representation (Orbital Diagram):

  $$\begin{array}{c c c c c c} \uparrow \downarrow & \uparrow \downarrow & \uparrow \downarrow & \uparrow \downarrow & \uparrow \downarrow & \uparrow \\ \text{1s} & \text{2s} & \text{2p}_x & \text{2p}_y & \text{2p}_z & \text{3s} \end{array}$$

• Excited State: An excited state occurs when an electron absorbs energy and moves to a higher energy orbital. One possible excited state for Sodium is when the 3s electron moves to the 3p orbital.

  $$\text{Configuration: } 1s^2 2s^2 2p^6 3p^1$$

  Representation (Orbital Diagram):

  $$\begin{array}{c c c c c c c c} \uparrow \downarrow & \uparrow \downarrow & \uparrow \downarrow & \uparrow \downarrow & \uparrow \downarrow & & \uparrow & \\ \text{1s} & \text{2s} & \text{2p}_x & \text{2p}_y & \text{2p}_z & \text{3s} & \text{3p}_x & \text{3p}_y & \text{3p}_z \end{array}$$