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1

Why do chemical bonds occur?

The particles have a lower potential energy bonded to eachother than they do separately

2

What are the forces between two molecules called and the forces acting within a molecule called?

Between two molecules- intermolecular
Within molecule- intramolecular

3

What does a higher boiling/melting point do to a molecules intermolecular forces?

They get stronger

4

Are intramolecular forces affected by physical changes such as adding heat?

No

5

What are the four categories chemical bonds can be separated into?

Nonpolar-covalent
Polar-covalent
Ionic
Metallic

6

What are nonpolar covalent bonds? What must the electronegativity difference be?

Occurs when two atoms have similar electronegativity values and share valence electrons
Non polar bond is when the electrons are shared equally
Electronegativity difference must be between 0 and 0.4

7

What are polar covalent bonds? What is their electronegativity difference?

Means that there are charged ends to a molecule
They share valence electrons but not equally
Electronegativity difference between 0.5 and 1.7

8

What are ionic bonds? What is their electronegativity difference?

They are so polar that electrons are transferred from one atom to another
Oppositely charged particles attack eachother
Formed between anions and cations
Electronegativity difference of 1.8 or higher

9

What are metallic bonds?

Formed between metal atoms
Do not follow octet rule
S and P orbitals overlap allowing electrons to move freely and be good conductors of heat

10

What is bond energy?

Energy required to break a bond to form neutral atoms

11

What is hybridization?

Hybrid orbitals are orbitals of equal energy produced by combining 2 or more orbitals on the same atom

12

What's the difference between ionic and molecular compounds?

Molecular- made of non metals
Ionic- metals and non metals

13

What are sigma and pi bonds?

When hybrid orbitals make bonds, they can be labeled as sigma or pi bonds
The first bonds always sigma bonds and are covalent bonds and can rotate
If there's double or triple bonds the second and third bonds are called pi bonds made from leftover unhybridized p orbitals

14

What is bond energy measured in?

kJ/mol

15

What is Lattice energy?

The energy released when 1 mole of ionic crystalline compound is formed from gaseous ions

16

Difference between lattice energy and bond energy

Bond energy is for molecules (n+n)
Lattice energy is for ions (m+n)

17

What is he order of bond strength weakest to strongest of these intermolecular bonds:
Ionic bonding
Dipole-dipole
Covalent bonding
Hydrogen bonding
London dispersion
Metallic bonding

1. London dispersion
2. Dipole dipole
3. Hydrogen bonding
4. Ionic bonding
5. Metallic bonding
6. Covalent bonding

18

What part of matter are inter molecular forces responsible for?

The bull properties of the whole substance not the individuals that make it
Surface tension, capillary action and Viscosity

19

What is London dispersion forces?
Example?

Weak attractive forces cause by instantaneous dipoles when electrons happen to end up on the same side of a molecule
This bond happens in all atoms and molecules even noble gases
Ex: h^2
O^2
Cl^2
Br^2

20

What are dipole dipole forces?
Example?

Occur between 2 polar molecules. They are the strongest out of the three intermolecular forces but are very weak compared to ionic and Metallic bonds
Ex: HCl

21

What are hydrogen bonding forces?
Examples?

Strong category or dipole-dipole forces.
Only occurs in H-F, H-O, and H-N bonds
The high difference in electronegativity between H and F,O,N makes very polar molecules and positive H is attracted to negative end of another molecule

22

Which is more dense? Solids or liquids?

Solids

23

What are the four types of crystals?

1. Ionic crystals
2. Covalent network crystals
3. Covalent molecular crystals
4. Metallic crystals

24

What are ionic crystals?

Composed of negative and positive ions
Are hard, brittle, good insulators, and have high melting points

25

What are covalent network crystals?

Composed of atoms covalently bonded (especially giant molecules)
Are very hard and brittle, have high melting points
Non conductors

26

What are covalent molecular crystals?

Composed of molecules covalently bonded
Low melting points, soft, good insulators

27

What are metallic crystals?

Metal atoms in ordered pattern with sea of electrons- are able to move throughout the crystal
Are good conductors
Varied melting points

28

Going from solid to liquid to gas what increases? What decreases?

Increases kinetic energy
Decreases intermolecular forces

29

Equal volumes of gases at the same temperature and pressure contain __________ number of particles

The same

30

At a constant temperature the volume of a sample _________ as the pressure ____________

Increases
Decreases