Covalent Bonding Test

what are unshared electron pairs called?

Lone Pairs

What is a bond?

A force that holds groups of two or more atoms together and makes the atoms function as a unit.

What is a ionic bond?

Attractions between oppositely charged ions.

What are covalent bonds?

What kind of materials bond?

Two non-metals bonding by sharing electrons.

What are non-polar covalent bonds?

Equal sharing of electrons.

What are polar covalent bonds?

Unequal sharing of electrons.

What are metallic bonds:

Electrostatic attraction between cations (2 metals).

Properties of covalent (molecular) compounds:

• what states of matter can they be found in?

• how are their melting and boiling points?

• how are they when conducting electricity

• are they soluble? in what?

• can be solids, liquids, or gases

• low melting and boiling points

• poor electrical conductors in all phases

• many soluble in non-polar liquids but not in water

Describe covalent networks in solids:

• why are they covalent?

• how are they structured?

• how are they “texture” wise

• soluble or insoluble?

• how are their melting and boiling points?

• covalent because of combinations with nonmetals

• interconnected

• very hard and brittle

• insoluble

• extreme melting and boiling points

describe covalent BONDS:

• how are they bonded?

• how can they be stable?

• share a pair of valence electrons by two atoms

• they can lead to stable molecules if they share electrons in which they create octets

What are polar covalent bonds?

• are the bonds equal or unequal?

• what atom does the electron typically spend the most time with?

• what happens if one atom is slightly more positive than the other?

• unequal

• the most electronegative one

• produces a dipole moment

Atoms with higher electronegativities hold onto their electrons more ________.

• tightly

Atoms with lower electronegitivity hold onto their electrons ______.

loosely

When elements pull harder on the shared electron, it gives them a:

partial negative charge or delta-

When elements do not hold their electrons as strongly, it gives them a:

partial positive charge

Covalent bonds that share electrons unevenly are (polar or un-polar)

polar covalent

Covalent bonds that share electrons evenly are (polar or non-polar)

non-polar

Polar vs. Non-Polar

describe:

• sharing of electron

• symmetrical or non-symmetrical

Polar:

• unequal sharing of electron

• non-symmetrical shape + lone pair on symmetrical atom

Non-Polar:

• equal sharing of electron

• symmetrical molecular shape

What is the VSEPR Theory

• a model used to predict the shape of molecules

• states that electron pairs around the central atom repel each other and arrange themselves as far as possible to minimize repulsion

Due to the VSEPR Theory, why do like-charged atoms repel each other?

• Electrons spread out to minimize repulsion.

• Lone pairs repel more than bonding pairs, which can distort molecular shapes.

• The molecular shape is determined by the arrangement of electron pairs around the central atom.

(repelling is the force between two similarly charged atoms)