Using group members to play the roles of nuclei and electrons, demonstrate the formation of an ionic bond between Na and Cl. Demonstrate the formation of the covalent bonds in H2O.

An ionic bond is a type of chemical bond where one atom, typically a metal, donates one or more electrons to another atom, usually a non-metal. This electron donation creates ions: atoms with a positive or negative charge due to the loss or gain of electrons.

Take the example of sodium chloride (NaCl). Sodium has one electron in its outer shell, making it eager to donate and achieve a stable electron configuration. Chlorine, on the other hand, has seven electrons in its outer shell and needs one more to be stable. When sodium donates its electron to chlorine, sodium becomes a positively charged sodium ion (Na+), and chlorine becomes a negatively charged chloride ion (Cl-). These ions attract each other due to opposite charges and form the ionic bond that holds NaCl together.

Unlike ionic bonds, covalent bonds involve the sharing of electron pairs between atoms. This type of bond typically occurs between non-metal atoms that have similar electronegativities—meaning they have similar tendencies to attract electrons.

Water (H₂O) is a classic example of covalent bonding. Here, the oxygen atom shares electrons with two hydrogen atoms. Oxygen needs two electrons to fill its outer shell, while each hydrogen atom has one electron to share. By sharing their electrons, the oxygen and the hydrogens fill their outer electron shells, resulting in a stable molecule where the shared electrons spend time in the outer orbitals of both oxygen and hydrogen atoms.

Electron transfer is the movement of electrons from one atom to another and is a fundamental aspect of chemical bonding. It's the key process in the formation of ionic bonds.

In the sodium chloride example, the electron transfer occurs when the single valence electron of a sodium atom moves over to the chlorine atom. This transfer is what transforms neutral atoms into charged ions that then attract each other to form an ionic compound. Electron transfer typically happens between elements that have a large difference in electronegativity because one atom is much better at attracting and keeping electrons than the other.

Valence electrons are the electrons found in the outermost shell of an atom. These electrons play a key role in chemical bonding, as they are the ones involved in forming bonds between atoms.

Atoms will often seek to either lose, gain, or share valence electrons to achieve a stable electron configuration, similar to that of noble gases, which have complete outer shells and are chemically inert. For example, sodium (Na), with one valence electron, seeks to lose it, while chlorine (Cl), with seven valence electrons, aims to gain one more. By doing so, both achieve a stable electron arrangement. In covalent bonding, such as in water, atoms share valence electrons to attain stability.