An element that can form ionic bonds is an element that can easily lose or gain electrons. This means that the element must have a low ionization energy or a high electronegativity. Some elements that can form ionic bonds include:

- Alkali metals (Group 1)

- Alkaline earth metals (Group 2)

- Halogens (Group 17)

- Oxygen (Group 16)

- Nitrogen (Group 15)

- Sulfur (Group 16)

For example, sodium (Na) can easily lose an electron to form a positively charged ion (Na+), while chlorine (Cl) can easily gain an electron to form a negatively charged ion (Cl-). When these two ions come together, they form an ionic bond.