Chem Chapter 8 & 9 Review

If you are only given the chemical formula of a compound, how can you usually determine if it is an ionic or covalent (molecular) compound?

A molecular formula will show how many of each element a molecule contains

Why do network solids have such high melting points?

Because they are crystals, and melting a network solid would require breaking covalent bonds throughout the solid. They are all held together by covalent bonds, making it very difficult to melt.

What causes dispersion forces?

Caused by the motion of the electrons

What atom has the lowest electronegativity?

Cesium

Name three weak forces that hold groups of molecules together.

Dispersion forces, Dipole Interactions, and Hydrogen Bonding

What atom has the highest electronegativity?

Fluorine

What group in the periodic table contains the most elements which exist as diatomic molecules?

Group 7A

What is the name of Group 7A?

Halogens

Do ionic compounds have high or low melting points?

High melting points

What kind of an atom does hydrogen have to be bonded to in order to form hydrogen bonds?

Highly electronegative atom, it also has to be small

Name an element that is not a member of this group that exists as a diatomic molecule, and is held together by the same type of covalent bond.

Hydrogen

Which of these bonds is the strongest? - Dispersion Forces - Dipole Interactions - Hydrogen Bonding

Hydrogen Bonding

Name the seven elements that exist as diatomic molecules, and state whether they are held together by a single, double, or triple covalent bond.

H—H, N- - -N: Triple, O--O: Double, F—F, Cl—Cl, Br—Br, I—I, Single

What is a coordinate covalent bond?

- A special type of covalent bond - Consists of a shared pair of electrons which originally came from only one of the atoms making up the bond

Give three examples of an atom that hydrogen has to be bonded to in order to form hydrogen bonds.

- Oxygen - Nitrogen - Fluorine

Are the elements in the Halogens group held together by a single, double, or triple covalent bond?

Single Covalent Bond

How does a covalent bond differ from an ionic bond?

The difference between an ionic and a covalent bond is that a covalent bond is formed when two atoms share electrons. Ionic bonds are forces that hold together electrostatic forces of attractions between oppositely charged ions. Ionic bonds have an electronegativity difference greater than or equal to 2. Covalent bonds have an electronegativity difference that is less than 2.

Which chemical bond is the weakest?

Dispersion forces

Which of these bonds is the weakest? - Dispersion Forces - Dipole Interactions -hydrogen Bonding

Dispersion forces

What is electronegativity?

A measure of the attraction of an atom for electrons in a covalent bond, and the shared electrons are more strongly attracted to the atom of greater electronegativity.

What kind of bond holds molecules together?

Covalent Bond

What is a covalent bond?

Covalent Bond: consists of a shared pair of electrons, A bond when two atoms share electrons, and it forms molecules

Which chemical bond is the strongest?

Covalent bonds

What kind of solid can be thought of as a huge molecule?

Network solids

Why do nonmetals share electrons?

Nonmetals want 8 electrons to be like the nearest noble gas

Name the three types of covalent bonds that can be distinguished from each other by means of the electronegativity difference between the bonded atoms.

Nonpolar covalent, moderately covalent, and very polar covalent

What type of elements are Halogens?

Salt producing elements

What are Van der Waals forces?

The two weakest attractions between molecules A.K.A.: - Dispersion Forces - Dipole Interactions

Why do metals transfer one or more electrons to nonmetals?

They want to attain 8 electrons to be like the nearest noble gas

Can a nonpolar molecule be made up of polar bonds? If your answer is yes, give an example.

Yes, can contain a polar bond if the molecule is symmetrical. An example of this is CO2