Test 6- Bonding

Question 1

Why do bonds form?

Answer 1

Energy! Atoms strive to be at lowest energy possible

Question 2

Diagram that shows relationship between potential energy level and distance between atoms

Answer 2

Be able to draw

Question 3

Chemical bond

Answer 3

Mutual electrical attraction between nuclei and valence (outer) electrons of different atoms. This binds the atoms together. All about valence electrons!

Question 4

Model to show chemical bonding

Answer 4

Lewis dot diagram shows elemental symbol and bonding VE

Question 5

Lewis Dot diagram basics

Answer 5

One dot per VE
--36
4???1
7???2
--58

Question 6

Stable electron configuration

Answer 6

• Same as nobel gas

- Elements lose or gain electrons to have the same number of electrons as a nobel gas

Question 7

Octet rule

Answer 7

• Elements strive for 8e- in outer energy level.
• some only need 2 e- to be stable like He
• Elements in part A of periodic table

Question 8

Exceptions to octet rule

Answer 8

• H only needs 2 e-
• B needs 6 e-
• Be needs 4 e-

Question 9

Electronegativity

Answer 9

Relative scale 0-4, the attraction an atom has for a pair of e- in a bond

• Increases up and right
• Electrons close to each other on periodic table share electron to meet the octet rule (covalent)

Question 10

Share electrons

Answer 10

• Similar electronegativity
• same area of the periodic table
• share e- to fufil octet rule
• covalent bond

Question 11

Transfer electrons

Answer 11

• Different electronegativity
• far apart on the periodic table
• Ionic bond

Question 12

Nonpolar covalent bond

Answer 12

• Perfect sharing
• Same attraction
• same electronegativity
• Electronegativity difference Range: 0-.4

Question 13

Polar covalent bond

Answer 13

• Unequal sharing

- Range: .4<_1.9

Question 14

Ionic bond

Answer 14

• Not sharing
• Complete transfer
• Range: above 1.9

Question 15

Drawing Ionic bonds

Answer 15

1. Draw lewis dot for both elements
2. transfer to make 8
3. Write both elements with brackets
4. Indicate the charge
   - Might have to draw more than one to make 8

Question 16

Characteristics of Ionic compounds

Answer 16

• Simplest piece is a Formula unit
• Crystal lattice AKA ionic latice
• Always solid at room temperature
• Soluble in water
• Conducts electricity
• High melting point

Question 17

Formula Unit

Answer 17

Simplest ration of the ions

Question 18

Crystal lattice AKA ionic latice

Answer 18

- Cluster of Na+ and Cl-
Na+Cl-Na+Cl-
Cl-Na+Cl-Na+
Na+Cl-Na+Cl-
- Not smooth

Question 19

Ionic compounds solids at room temperature

Answer 19

So strongly attracted that it takes a lot of energy to separate

Question 20

Ionic compounds soluble in water

Answer 20

Water has a great attraction to the compound and the high energy breaks them apart. (Brad Pitt and Angelina Jolie)
- NaCl(s) –> NaCl(aq)

Question 21

Ionic compounds conducting electricity

Answer 21

• Solution of ions and liquid ionic compounds
• has to be s solution or melted/liquid
• Triangle of battery, light, and beaker with solution with wires going into the solution

Question 22

Nomenclature

Answer 22

• Naming/writing formulas

- IUPAC- International Union of Pure and Applied Chemists

Question 23

Naming Ionic compounds

Answer 23

• Binary
• Name metal first
• When writing a formula, the net charge for all compounds is zero
• Subscript indicates number of atoms/ions of the element it follows
• Criss cross- use charge as subscript of other element

Question 24

Binary

Answer 24

• Ionic
• 2 elements
• Metal and nonmetal
• End in ide
• name nonmetal and change ending to ide

Question 25

Naming transitional metals

Answer 25

Use roman numerals to indicate charge of metal ion

Question 26

Tertiary Ionic compounds

Answer 26

- More than 2 elements - cation(+)/anion(-) - Don't end in ide - All contain polyatomic ions

Question 27

Naming representative metals

Answer 27

- more than 2 elements - Name metal and name polyatomic ion - Subscript doesn't matter - Not all compounds that end in Ide are not binary but all binary compounds end in ide - If you have more than one polyatomic ion, it must be in parenthesis

Question 28

Transitional metals with polyatomic ions

Answer 28

Use roman numerals to indicate charge

Question 29

Covalent bonds

Answer 29

- Occur between 2 nonmetals (in general) - 2 types of covalent bonds based on electronegativity difference - 0-.4= nonpolar covalent bond, equal sharing - 0<_1.9= polar covalent bond unequal sharing - Exist as individual molecules - Molecule=smallest piece of covalently bonded particle

Question 30

Smallest piece of covalent vs. Ionic

Answer 30

- Covalent= molecule | - Ionic= Formula unit

Question 31

Representing e- sharing covalent bond with a lewis dot diagram

Answer 31

- Still all atoms strive for 8e- - No transfer - No charges or brackets - Dots and circles - Covalent bond is the overlap - e- always shared in pairs - Single if one pair is shared - Double if two pairs are shared - Triple if three

Question 32

Line structure

Answer 32

Each line represents a pair of electrons

Question 33

Lewis Dot for polyatomic ions

Answer 33

- have circles (2 nonmetals) and brackets (charge) - Lower electronegativity goes in the middle - Add/subtract electrons according to charge

Question 34

Coordinate covalent/Dative bonds

Answer 34

Both shared electrons are from one element

Question 35

Lewis Dot and Line are both

Answer 35

structural diagrams