Chemical Bonding

sciene unit 3 test

electronegativity ____ going across a period

increases

electronegativity ____ going down a group

decreases

how does electronegativity inolve the noble gases

it doesn’t

**What are covalent bonds?**

Pairs of electrons are shared equally between nonmetals due to minimal or no difference in electronegativity

**What are polar covalent bonds?**

Pairs of electrons shared unequally between nonmetals due to small differences in electronegativity

**What is electronegativity?**

A measure of the tendency of an atom to attract a bonding pair of electrons

**What is a molecule?**

The smallest unit of a covalent compound

**What is a dipole?**

Slight charge (positive or negative) on a molecule to unequal sharing of electrons

**Which element has the highest electronegativity and what is its value?**

Fluorine - 4.0

**Which element has the lowest electronegativity and what is its value?**

Francium - 0.7

**What is a bond?**

A force of attraction that holds two or more atoms together

**What is a chemical bond a result of?**

EMF

During bonding electrons are…

Gained, lost, or shared between elements

**Why does an element bond?**

To achieve octet

**What do covalent bonds form between?**

Nonmetals

How are electrons involved in covalent bonds

valence electrons are fairly equally shared

How is EMF involved in covalent bonds

EMF is between nuclei and shared electrons (intramolecular force)

**What is the electronegativity difference for covalent bonds**

Less than .4 difference, zero to no difference

**What is the shape/base unit of covalent bonds**

Molecule

**What are compound properties for covalent bonds**

Low mp/bp, high volatility, low conductivity, low solubility

**What do PCB form between?**

Nonmetals

**How are electrons involved in PCB?**

Unequal sharing of pairs of valence electrons

**What are forces in PCB?**

**What are forces in PCB?**

**Why does intermolecular force form?**

Forms due to unequal sharing which forms dipoles

**What is the electronegativity difference for PCB?**

Small

**What is the shape/base unit of PCB?**

Molecule with dipoles

**What are the properties for PCB?**

Medium mp/bp, medium volatility, medium-low conductivity, medium solubility

**One?**

Mono

**Two?**

Di

**Three?**

Tri

**Four?**

Tetra

**Five?**

Penta

**Six?**

Hexa

**Seven?**

Hepta

**Eight?**

Octa

**Nine?**

Nona

**Ten?**

Deca 

**What does the second nonmetal end change to?**

\-ide 

**Hydrogen?**

Hydride

**P2F6?**

**Diphosphorus Hexafluoride**

C3H8

Tricarbon Octahydride 

**BrCl5?**

Bromine Pentachloride

N2F4

**Dinitrogen Tetraflouride**

N2F4

**Dihydrogen Monoxide**

H2O

dihyrogen monoxide

**Selenium Tetrabromide?**

SeBr4

**Pentaphosphorous Decoxide?**

P5O10

**Triiodine Heptafluoride?**

I3F7

what is melting point?

temp at which substance goes from solid to liquid

what is conductivity

ability to conduct heat or electricity

what is solubility

ability to dissolve in a liquid

what is volatility

ability to turn into a gas

what does metallic bonds form between?

metals and metals

how are electrons involved in metallic bonding?

all valence electrons shared in a common “sea/pool”

how do you describe the attraction in metallic bonding?

attraction between positive nuclei and shared electrons is very fluid

what is the electronegativity difference for metallic bonds?

minimal to none, similar electronegativities

what is the base unit for metallic bonds?

atoms, sometimes metallic crystals/lattices

what is the mp/bp for metallic bonds?

high

what is the volatility for metallic bonds?

low

what is the conductivity for metallic bonds?

high

what is the solubility for metallic bonds?

low

what do ionic bonds form between?

metals and nonmetals, opposite ions

how are electrons involved in ionic bonding?

nonmetal takes electron from metal (electron transfer)

why do elements go through electron transfer?

to get to octet

what is the electronegativity difference for nonmetals?

nonmetals have larger electronegativity, metals have smaller electronegativity, big electronegativity difference

what is the shape/base unit for ionic bonds?

crystal lattice

what is the mp/bp for ionic bonds?

high because it takes lots of energy to break apart crystal lattice

what is the volatity for ionic bonds?

low

what is the conductivity for ionic bonds?

low if solid, high if dissolved/molten because H20 rips apart the crystal lattice

what is the solubility for ionic bonds?

high

what will alike charges do?

repel

what will opposite charges do?

attract and stick together

what is a positive ion called?

cation

a cation will be formed from an atom that has the tendency to…

lose electrons

atoms that lose electrons are usually…

metals

metals are found on what side of the table?

left side of the table

what are negative ions called?

anions

anions will be formed from an atom that has a tendency to…

gain electrons

atoms that gain electrons are usually…

nonmetals

nonmetals are found on what side of the table?

right

when multiple ion pairs are attracted to each ohter what does it form?

an ionic crystal

does ionic bonding produce molecules

no

what is the formula unit?

smallest ratio of ions

metals … their electrons

give away

nonmetals … electrons

take

when an atom gives an electron, you write:

\+1

when an atom takes an electron, you write:

\-1

what can the number of elements in a bond can be determinded by?

the amount of bonds that need to be made

what is a monatomic ion?

single atom forming an ion

what is the charge on a monatomic ion?

it’s oxidization number

what is an example of a monatomic ion?

H+1

what is a polyatomic ion?

group of covalently bonded atoms that carries a new charge

what do polyatomic ions form bonds with?

forms ionic bond with another ion

ammonium

NH4+1

bicarbonate

NCO3-1

hydroxide

OH-1

nitrate

NO3-1

bisphosphate

NPO4-2

carbonate

CO3-2

chromate

CrO4-2