Which of the following are likely to form an ionic bond?

copper atoms
hydrogen atoms
hydrogen and oxygen atoms
copper and fluorine atoms

Ionic bond is formed by metals and non metals so copper reacts with fluorine by donating 2 electrons to two fluorine atoms so as to gain an octet structure.
Cu + Fl₂→ CuFl₂
Cu²⁺ + Fl⁻→ CuFl₂
copper atoms have metallic bonds so also hydrogen atoms. while hydrogen and oxygen atoms have covalent bonds.

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