Ch 8: Chemical Bonding I: Basic Concepts

Question 1

Swedish chemist, Alfred Nobel died in 1896, and his will specified that the bulk of his considerable fortune be used to establish prizes that bear his name. The prizes are given annually in what 5 categories?

Answer 1

chemistry
physics
physiology/medicine
literature
peace

p. 325

Question 2

Two species are said to be isoelectronic if they have the same…

Answer 2

…electron configuration.

p. 326

Question 3

In ionic bonding, electrons are ________.

In covalent bonds, electrons are ______.

Answer 3

transferred

shared

Question 4

Why are valence electrons the ones used in chemical bonding?

Answer 4

Because these electrons are loosely bound to the atom.

Question 5

What interesting observation can we make about the number of valence electrons in an atom of a particular element and it’s group number?

Answer 5

For most elements, the number of valence electrons is the same as the element’s group number.

e.g. Li has 1 e, and is in group 1A
C has 4 e’s and is in group 4A
O has 6 e’s and is in group 6A

Question 6

Atoms of elements with widely different electronegativities tend to form _____ compounds with each other because the atom of the less electronegative element gives up its electrons to the atom of the more electronegative element. Atoms of elements with comparable electronegativities tend to form polar covalent bonds or simply polar bonds, with each other because the shift in electron density from one atom to the other is usually small. Only atoms of the same element, which have the ____ ____________, can be joined by pure covalent bond.

Answer 6

ionic

same electronegativity

Question 7

There is no sharp distinction between nonpolar covalent and polar covalent or between polar covalent and ionic, but the following guidelines can help distinguish among them:

A bond between atoms whose electronegativities differ by less than ___ is generally considered purely covalent or nonpolar.

Answer 7

0.5

Question 8

A bond between atoms whose electronegativities differ by the range of 0.5 to 2.0 is generally considered _____ ______.

Answer 8

polar covalent

p. 338

Question 9

Bonds between atoms whose electronegativities differ by 2.0 or more is generally considered _____.

Answer 9

ionic

p. 338

Question 10

Sometimes chemists describe bonds using the term percent ionic character. A purely ionic bond would have 100% ionic character (although no such bond ______). A purely covalent nonpolar bond has _% ionic character.

Answer 10

exists

0