onic bonds form between what two types of elements?
➤ Metal and nonmetal
Covalent bonds form between what types of elements?
Two nonmetals
What makes a bond polar?
Unequal sharing of electrons.
What two elements form a metallic bond?
Two or more metals
What does a chemical formula show?
The elements in a compound and their ratios.
What happens to electrons during ionic bonding?
They are transferred from one atom to another.
What is a molecule?
A neutral group of atoms joined by covalent bonds.
What makes a bond nonpolar?
Equal sharing of electrons.
What is the “sea of electrons”?
Valence electrons that move freely among metal ions.
What does a subscript in a formula indicate?
The number of atoms of each element.
What type of ion forms when an atom gains electrons?
An anion (negative ion)
How do atoms achieve stability in covalent bonding?
By sharing valence electrons.
What happens to electron distribution in a polar molecule?
One side becomes slightly negative, the other slightly positive.
What is an alloy?
A mixture of two or more metals.
What structure do ionic compounds form?
Crystal lattice.
Why do ionic compounds have high melting points?
Strong attractions between oppositely charged ions in a crystal lattice.
What’s the difference between a single, double, and triple bond?
They share one, two, or three pairs of electrons respectively.
What determines if a molecule is polar or nonpolar?
Type of atoms and the shape of the molecule.
Why are metals good conductors of electricity?
Free electrons carry electrical current easily.
Give one property of metallic compounds.
Malleable, ductile, good conductor, high melting point.
Explain why ionic compounds conduct electricity only when melted or dissolved.
Ions are free to move and carry charge in liquid or solution form.
Why do covalent compounds generally have low melting points?
Weak attractions between individual molecules.
Why do polar molecules have stronger attractions than nonpolar ones?
Opposite partial charges attract each other.
How do alloys differ from pure metals?
Alloys are stronger/harder due to distorted lattice layers.
Compare the strength of attractions: ionic, covalent, metallic.
Ionic strongest, metallic moderate, covalent weaker.