Answer:
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Step-by-step explanation:
In covalent bonding, atoms share electrons from their last shell to other atoms to gain stability.
Chlorine has 7 electrons in its last shell, it needs to gain 1 electron to become stable.
Group 1 elements have 1 electron in their last shell, they need to lose 1 electron to become stable.
Group 1 elements can bond with chlorine.