che exam 1 ch 4

Tetra

4

Penta

5

Hexa

6

Hepta

7

Octa

8

Nona

9

Tri

3

Ozone, O3 can be drawn as ________ resonance structures, and is considered a ________ molecule.

2, neutral

Mono

1

Atoms with 1, 2, or 3 valence electrons generally form how many bonds?

1,2, or 3

Deca

10

Di

2

Electron dot structures for molecules are aka:

Lewis Structures

An atom surrounded by 2 groups is ___________, and has a bond angle of___________.

Linear, 180

How do you refer to a molecule/ion that has 2 or more resonance structures?

Resonance stabilized

What are Resonance Structures?

Two Lewis Structures having the same arrangement of atoms, but a different arrangement of electrons.

Are there exceptions to the Octet Rule?

Yes

What is the difference between a molecular formula and a lewis structure?

a lewis structure shows the connectivity between atoms, where molecular shows the number and identity of atoms.

What does a solid line between two element symbols represent?

a two electron bond

Elements in the 3'rd row can have more than 8 electrons around them, why?

bc they have empty d orbitals available to accept electrons around them.

Electronegativity _________ down a column of the periodic table.

decreases

Atoms with 4 or more valence electrons form __________ bonds to give them an octet.

enough

The most stable arrangement of atoms keeps the groups closest or furthest away as possible?

furthest

To decide the molecular group of an atom you count the number of ____________, number of _______________, number of ___________, _____________, and approx. ____________ angle.

groups, atoms, lone pairs, shape, bond

What is a diatomic molecule?

hydrogen, bc it contains just 2 atoms.

Give an example of an exception to the octet rule, if there can be?

hydrogen, because it accommodates only 2 electrons when bonding, elements in the 3'rd row also, bc they do not have enough valence electrons to form an octet in a neutral state.

Electronegativity __________ across a row in the period table.

increases

How does a Resonance Structure stabilize a molecule?

it spreads out lone pairs, and electron pairs in multiple bonds over a larger region of space.

Define electronegativity:

measure of an atom's attraction for electrons in an bond. tells how much a particular atom "wants" electrons

Covalent bonds form when two or more ____________ combine.

nonmetals

Covalent bonds are also formed when a ___________ and a ____________ combine.

nonmetals, and metalloid

An atom surrounded by 4 groups is _______________, and has bond angles of _________________.

tetrahedral, 109.5

How do Resonance Structures differ?

the location of multiple bonds, and position of lone pairs.

An atom surrounded by 3 groups is _____________, and has bond angles of _____________.

trigonal planar, 120

A covalent bond forms when two or more atoms share electrons. true or false?

true

A molecule is a discrete group of atoms held together by covalent bonds. true or false?

true