Alright, let's go through the electron configuration of Magnesium (Mg) step-by-step.
### Step 1: Identify the Atomic Number
Magnesium has an atomic number of 12, which means it has 12 electrons in a neutral atom.
### Step 2: Write the Longhand Notation
The electrons in an atom fill the atomic orbitals in a specific order based on increasing energy levels and sublevels. For magnesium with 12 electrons, the longhand notation involves filling the orbitals in the following sequence:
1. 1s Orbital:
- The 1s orbital can hold a maximum of 2 electrons.
- Configuration: [tex]\(1s^2\)[/tex]
2. 2s Orbital:
- The 2s orbital also holds a maximum of 2 electrons.
- Configuration: [tex]\(2s^2\)[/tex]
3. 2p Orbital:
- The 2p orbital can hold a maximum of 6 electrons.
- Configuration: [tex]\(2p^6\)[/tex]
4. 3s Orbital:
- The 3s orbital is the next to fill after the 2p orbital and can hold a maximum of 2 electrons.
- Configuration: [tex]\(3s^2\)[/tex]
Combining these configurations, the longhand notation for magnesium is:
[tex]\[ 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \][/tex]
### Step 3: Write the Noble-Gas Notation
The noble-gas notation uses the electron configuration of the nearest noble gas with a lower atomic number as a reference point. For magnesium, the nearest noble gas with a lower atomic number is neon (Ne), which has the electron configuration [tex]\( 1s^2 \, 2s^2 \, 2p^6 \)[/tex].
Using this as the core configuration, we then add the remaining configuration:
- Neon (Ne): [tex]\( [Ne] \)[/tex]
- Remaining electrons: [tex]\( 3s^2 \)[/tex]
Thus, the noble-gas notation for magnesium is:
[tex]\[ [Ne] \, 3s^2 \][/tex]
### Summary
- Longhand notation for Magnesium (Mg): [tex]\( 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \)[/tex]
- Noble-gas notation for Magnesium (Mg): [tex]\( [Ne] \, 3s^2 \)[/tex]
