Chapter 10: Chemical Bonding

Question 1

List the two types of chemical bonds

Answer 1

ionic and covalent

Question 2

Tell how the two ions in an ionic bond are held together.

Answer 2

negative and positive charged ions are attracted to each other (like a magnet)

Question 3

Tell how the two atoms in a covalent bond are held together.

Answer 3

They share a pair of valence electrons

Question 4

Distinguish between single covalent bonds, double covalent bonds, and triple covalent
bonds.

Answer 4

A single covalent bond is when two atoms share one pair of valence electrons. Double covalent bonds are when two atoms share two pairs of valence electrons. Triple covalent bonds are when two atoms share three pairs of covalent electrons.

Question 5

Describe octet rule

Answer 5

atoms prefer to have 8 valence electrons in their outermost shell.

Question 6

There are exceptions to the octet rule

Answer 6

Hydrogen only has 1 valence electrons and can be bonded without having 8 valence electrons. Boron only has 3 valence electrons prefers 6 valence electrons in its outermost shell.

Question 7

Describe a Lewis structure, also called a Lewis symbol or a Lewis electron dot symbol.

Answer 7

A way to show how atoms share electrons when they make molecules

Question 8

Tell the difference between bonding pair electrons and lone pair electrons.

Answer 8

bonding pair electrons are electrons that are shared between atoms. Lone pair electrons are not shared between atoms.

Question 9

Determine the formal charge on the atoms in a molecule based on its Lewis structure.

Answer 9

the number of valence electrons in the neutral atom) minus (the number of covalent bonds around the atom) minus (the number of unshared electrons around the atom)

Question 10

Describe the meaning of resonance structures.

Answer 10

Different resonance structures for a molecule are
possible because of the presence of a double bond that can be moved to a different location in the structure without changing the position of the atoms present

Question 11

What is the basis of VSEPR?

Answer 11

the idea that valence electrons tend to repel each other

Question 12

By knowing VSEPR, what can be predicted?

Answer 12

Is used to predict the three-dimensional shape of a molecule

Question 13

Explain the difference between electron geometry and molecular geometry.

Answer 13

Electron geometry is the position of electrons around the central atom. Molecular geometry is the position of the atoms around the central atom

Question 14

Recognize the differences between these basic geometries: linear, trigonal planar, and tetrahedral

Answer 14

Linear is a Lewis structure that is straight 180 degrees (3 molecules). Trigonal planar is 3 molecules bonded to central atom which has a lone pair. Tetrahedral has 3 atoms bonded to a central atom that does not have a lone pair

Question 15

After drawing a correct Lewis structure of a molecule, use the VSEPR guidelines to predict the electronic geometry of simple molecules.

Answer 15

Electron geometry and molecular geometry are the same when there are no lone electron pairs on the central atom.

Question 16

Define electronegativity

Answer 16

the ability for atoms to attract electrons to itself

Question 17

Tell the periodic trends for electronegativity.

Answer 17

electronegativity increases from left to right across a period

Question 18

Using electronegativity values, determine which atom has a partial negative charge and which atom has a partial positive charge in their covalent bond.

Answer 18

the atom with greater electronegativity becomes a partial negative charge. Whereas the atom with lesser electronegative has a partial positive charge.

Question 19

Define a polar covalent bond.

Answer 19

A covalent bond that has unequally distributed electrons, unequal attraction between electrons, and are not symmetrical.

Question 20

Based on absolute value of the electronegativity difference between two atoms, classify
the bond as covalent, polar covalent, or ionic

Answer 20

covalent (nonpolar) if EN difference is > 0.5. Polar bonds have EN difference between 0.5 and 1.9. Anything above that is ionic

Question 21

Based Lewis structure, electronegativity differences and molecular geometry, predict whether a molecule is polar or non-polar.

Answer 21

A molecule is polar if there are covalent bonds present and nonsymmetrical.