Answer
Missing atom: $^{1}_1H$
Complete nuclear equation:
$^4_2He + ^{27}_{13}Al --\gt ^{30}_{14}Si + ^1_1H$
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.
$4 + 27 = 30 + ?$
$31 = 30 + ?$
$31 - 30 = ?$
$1 = ?$
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.
$2 + 13 = 14 + ?$
$15 = 14 + ?$
$15 - 14 = ?$
$1 = ?$
3. Identify the symbol of the element with atomic number equal to 1 (Use a periodic table):
- It is "H".
4. Write the symbol with the atomic and mass numbers, and write the complete nuclear equation:
$^{1}_1H$
$^4_2He + ^{27}_{13}Al --\gt ^{30}_{14}Si + ^1_1H$
