Answer
Missing atom: $^{23}_{12}Mg$
Complete nuclear equation:
$^{23m}_{12}Mg--\gt ^{23}_{12}Mg + ^0_0 \gamma$
Work Step by Step
1. Calculate the mass number of the missing atom.
- The sum of the mass numbers on the right side must be equal to that on the left side.
$23 = ? + 0$
$23 = ?$
2. Calculate the atomic number of the missing atom.
- The sum of the atomic numbers on the right side must be equal to that on the left side.
$12 = ? + 0$
$12 = ?$
3. Identify the symbol of the element with atomic number equal to 12 (Use a periodic table):
- It is "Mg".
4. Write the symbol with the atomic and mass numbers, and write the complete nuclear equation:
$^{23}_{12}Mg$
$^{23m}_{12}Mg--\gt ^{23}_{12}Mg + ^0_0 \gamma$