Valence Electrons
The electrons that exist farthest from an atom’s nucleus. They are the electrons with the highest energy level number.
What determines an atom’s chemical behavior?
The number of valence electrons it has.
What atoms have the same number of valence electrons?
The atoms in the same column in the periodic table of elements.
Octet rule
Most atoms strive to attain 8 valence electrons.
Ion
An atom that has gained or lost electrons, becoming electrically charged.
Cation
A positively charged ion.
Anion
A negatively charged ion.
Ionization
The process by which an atom turns into an ion by gaining or losing electrons.
Ionization energy
The amount of energy needed to take and electron away from an atom.
Periodic property
A characteristic of atoms that varies regularly across the periodic table.
Electronegativity
A measure of how strongly an atom attracts extra atoms to itself.
How does the electronegativity of atoms increase?
From right to left on the periodic table.
Which elements are made of homonuclear diatomic molecules, rather than individual atoms?
Nitrogen, oxygen, chlorine, flourine, bromine, iodine, astatine, and hydrogen.
Covalent Bonds
A shared pair of valence electrons that holds atoms together in covalent compounds.
What is the difference between covalent compounds and ionic compounds?
The atoms in covalent compounds share electrons to form molecules, while the atoms in ionic compounds give and take electrons to form ions.
