During a chemical reaction, the atomic number of each element involved remains the same. The atomic number is a fundamental property of an element and represents the number of protons in the nucleus of an atom. It determines the identity of the element.
In a chemical reaction, atoms are rearranged and bond with other atoms to form new compounds, but the number of protons in each atom remains constant. This is because chemical reactions involve the breaking and formation of chemical bonds, which are due to the interactions of electrons, not protons in the nucleus.
For example, in the reaction between hydrogen (H2) and oxygen (O2) to form water (H2O):
2H2 + O2 → 2H2O
The atomic number of hydrogen is 1, and the atomic number of oxygen is 8. The reactants and products have the same atomic numbers for hydrogen and oxygen, indicating that the identity of the elements does not change.
While chemical reactions involve changes in the arrangement of atoms and the formation of new substances, the fundamental composition of the atoms, including their atomic numbers, remains constant throughout the reaction.