• When a metal and a nonmetal bond, they do not share electrons. Instead one or more valence electrons transfers fro the metal atom to the nonmetal atom.
• After electrons transfer the atoms bond and form a chemically stable compound.
• When an atom loses or gains a valence electron it becomes an ion.
• An ion is an atom that is no longer electrically neutral because it has lost or gained valence electrons.
• An atom that loses valence electrons becomes an ion with a positive charge.
• An atom that gains valence electrons becomes an ion with a negative charge.
Losing valence electrons
• The info you can infer about sodium by looking at the periodic table is that it’s a metal, its atomic number is 11 which means that it has 11 protons and 11 electrons. • Sodium is in group 1 on the periodic table so sodium atoms have 1 valence electron and they are chemically unstable. • Metal atoms become more stable when they lose valence electrons and form a chemical bond with a nonmetal. • If a sodium loses its 1 valence electron it would have a total of 10 electrons.
Gaining valence electrons
• If a chlorine atom gains 1 valence electron it will have 8 valence electrons and it will have the same electron arrangement as the noble gas argon. • When a sodium atom loses a valence electron it becomes a positively charged ion.
• When a chlorine atom gains a valence electron it becomes a negatively charged ion.
Determining an ions charge
• Atoms are electrically neutral because they have the same number of protons and electrons.
• Once an atom gains or loses electrons it becomes a charged ion.
• To determine the charge subtract the number of electrons in the ion from the number of protons.
Ionic bonds- Electron transferring
• When forming a chemical bond the nonmetal atoms gain the electrons lost by the metal atoms.
• The attraction between positively and negatively charged ions in an ionic compound is an ionic bond.
• Ionic compounds are usually solid and brittle at room temperature. • They have relatively high melting and boiling points.
• Many ionic compounds dissolve in water.
• Water that contains dissolved ionic compounds is a good conductor of