Answer:
Na, Cu, and Br will form positive ions
Step-by-step explanation:
Na, Cu, and Br have more protons than electrons, so they will form positive ions.
Na, Cu, and Br are all elements that have an atomic number greater than their number of electrons. This means that they have more protons than electrons, so they will form positive ions when they react with other elements. Na will form Na+, Cu will form Cu+ and Br will form Br+.