How do valence electrons affect the properties of atoms?
Valence electrons determine whether an atom forms cations, anions, or covalent compounds.
- One to three valence electrons — tend to form positive ions.
- Five to seven valence electrons — tend to form negative ions.
- Four valence electrons — form covalent bonds
The number of electrons in an atom's outermost valence shell governs its chemical properties.
This tendency is called the octet rule, because the atoms have eight valence electrons.
The most reactive metallic elements are metals from Group 1 (e.g.,
These elements can lose one or two valence electrons to form a positive ion with an
The most reactive nonmetals are in Groups 17 (e.g.,
They need only one or two additional valence electrons to form a negative ion with an
GROUP 14 ELEMENTS
Elements in Group 14 (e.g.,
This requires too much energy.
Instead, they gain their octets by sharing electrons in covalent bonds with other nonmetals (e.g.,