Unit 2 Vocab

Question 1

Cohesion

Answer 1

the attraction of molecules for other molecules of the same kind

Question 2

Adhesion

Answer 2

the attraction between two dissimilar phases. ex.) Water is attracted to other substances than water

Question 3

Properties of water

Answer 3

• Its polarity
• Its cohesive and adhesive properties
• It’s high specific heat
• It’s surface tension

Question 4

Ionic Bonds

Answer 4

• Occurs between two atoms that are attracted to each others opposite charge
• Often occur between metals and nonmetals

Question 5

Metallic Bonds

Answer 5

When a group of metal atoms share a cloud of valence electrons

Question 6

Interstitial alloy

Answer 6

When metal atoms with two vastly different radii combine

Question 7

Substitutional alloy

Answer 7

When metal atoms with similar radii combine

Question 8

Covalent Bonds

Answer 8

• Two atoms share electrons
• Each atom counts the shared electrons as part of its valence shell
• Both atoms achieve complete outer shells

Question 9

Sigma bond

Answer 9

All single, covalent bonds

Question 10

Pi bonds

Answer 10

All covalent bonds with a double or triple bond

Question 11

Internuclear distance

Answer 11

The distance between two nuclei in a molecule

Question 12

Network solid

Answer 12

• Held together by a lattice of covalent bonds
• Very high melting and boiling point
• Very hard

Question 13

Network (Covalent) Bonds

Answer 13

• Atoms are bonded by covalent bonds in a continuous network extending throughout the material
• Looks like a lattice

Question 14

Lewis Dot Structures

Answer 14

Diagrams that show the bonding between atoms of a molecule, as well as the lone pairs of electrons that may exist in the molecule

Question 15

Resonance Forms

Answer 15

• Used when there is more than one way to place double bonds and lone pairs on atoms
• Another way of drawing a Lewis dot structure

Question 16

Incomplete Octets

Answer 16

Atoms that are stable with less than eight electrons in their outer shell

Question 17

Expanded Octets

Answer 17

In molecules that have d subshells available, the central atom can have more than eight valence electrons, but never more than twelve.

Question 18

Formal Charge

Answer 18

Used when there is more than one Lewis structure for a molecule, you must use formal change to determine the more likely structure
- Take the number of valence electrons for that atom and subtract the number of assigned electrons in the Lewis structure
- When counting assigned electrons, lone pairs count as two and bonds count as one
- The fewer number of atoms there are with an actual formal charge the more likely the structure will be

Question 19

Molecular Geometry

Answer 19

The three-dimensional arrangement of the atoms that constitute a molecule.

Question 20

Valence shell electron-pair repulsion (VSEPR)

Answer 20

a model used to predict 3-D molecular geometry based on the number of valence shell electron bond pairs among the atoms in a molecule or ion

Question 21

Linear basic shape

Answer 21

If the central atom has 2 electron pairs, then it has sp hybridization and its basic shape is linear

Question 22

Trigonal Planar basic shape

Answer 22

If the central atom has 3 electron pairs, then it has sp squared hybridization and its basic shape is trigonal planar; its bond angles are about 120 degrees

Question 23

Tetrahedral basic shape

Answer 23

If the central atom has 4 electron pairs then it has sp to the third power hybridization and its basic shape is tetrahedral; its bond angles are about 109.5 degrees

Question 24

Trigonal bipyramidal basic shape

Answer 24

If the central atom has 5 electron pairs, its basic shape is trigonal bipyramidal

Question 25

Octahedral basic shape

Answer 25

If the central atom has 6 electron pairs, its basic shape is octahedral

Question 26

Potential energy

Answer 26

potential energy is the energy held by an object because of its position relative to other objects