When two atoms approach each other, they combine only under condition that there should be:
Increase in potential energy
Increase in kinetic energy
Decrease in potential energy
Increase in kinetic energy.
It is a fundamental truth that all-natural systems tend to lose potential energy and become more stable. It is an observed fact that a bonded state is more stable than an unbonded state. This is due to the fact that the bonded state has lower potential energy than the unbonded state. Hence, when two atoms approach each other, they combine only under the condition that there is a decrease in potential energy.
Therefore, option number (3) is correct.
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