CHEMICAL BONDS AND COMPOUNDS

Question 1

Four periodic table sections

Answer 1

• Representative Elements
• Noble - gas Elements
• Transition Elements
• Inner Transition Elements

Question 2

Compounds are divided into two broad categories:

Answer 2

Ionic compounds
Molecular compounds (Covalent)

Note: Certain combinations of elements produces ionic compounds, some other combinations form molecular compounds

Question 3

the attractive force that holds two atoms together in a more complex unit

Answer 3

Chemical bond

note: It is important to note that most bonds are not 100% ionic or 10% covalent

Question 4

Two types of chemical bond

Answer 4

Ionic bonds
Covalent bonds

Question 5

formed through transfer of one or more electrons from one atom or group of atoms to another

Answer 5

Ionic bonds

Question 6

formed through the sharing of one or more pairs of electrons between two atoms

Answer 6

Covalent bonds

Question 7

There are two fundamental concepts to understanding ionic and covalent bonding models

Answer 7

1. Not all electrons in an atom participate in bonding. Those that do are called valence electrons
2. Certain arrangements of electrons are more stable than others, as is explained by the octet rule

Question 8

an electron in the outer-most electron shell of a representative or noble-gas element

Answer 8

Valence electron

Question 9

The number of valence electrons in an atom of a representative element can be determined from the atom’s what

Answer 9

electron configuration

Question 10

the chemical symbol of an element surrounded by dots equal in number to the number of valence electrons present in atoms of the element

Answer 10

Lewis symbol

Question 11

The General Practice in writing lewis symbol

Answer 11

The general practice in writing these symbols is to place the first four dots separately on the four sides of the chemical symbol and then begin pairing the dots are further dots are added

Question 12

Lewis Symbol: Three things to note:

Answer 12

1. Representative elements in the same group of the periodic table have the same number valence electrons
2. The number of valence electrons for the representative elements is the same as the Roman numeral periodic-table group number
3. The maximum number of valence electrons for any element is eight

Question 13

produced as a result of ionic bonding

Answer 13

Ions

Question 14

an atom (or group of atoms) that is electrically charged as a result of the loss or gain of electrons

Answer 14

An ion

Question 15

If an atom gains one or more electrons, it becomes

Answer 15

a negatively charged

Question 16

if an atom loses one or more electrons, it becomes

Answer 16

a positively charged

Question 17

Loss of one, two, or three electrons gives ions

Answer 17

with +1, +2, or +3 charges, respectively

Question 18

Gain of one, two, or three electrons gives ions

Answer 18

with -1, -2, or -3 charges, respectively

Question 19

This kind of atom is containing one, two, or three valence electrons
(Groups IA, IIA, and IIIA) tend to lose electrons to acquire a noble gas electron configuration

Answer 19

Metal Atoms

Question 20

Group IA metals form how many ions

Answer 20

1+ ions

Question 21

Group IIA metals form how many ions

Answer 21

2+ ions

Question 22

Group IIIA metals form how many ions

Answer 22

3+ ions

Question 23

This kind of atom is containing five, six, or seven electrons
(Groups VA, VIA, and VIIA) tend to gain electrons to acquire a noble gas electron configuration

Answer 23

Non-metal atoms

Question 24

Group VIIA nonmetals form how many atoms

Answer 24

1- atoms

Question 25

Group VIA nonmetals form how many atoms

Answer 25

2- ions

Question 26

Group VA nonmetals form how many ions

Answer 26

3- ions

Question 27

Elements in this group would have to gain or lose four electrons to attain stability, but in most cases the bonding that results is more adequately described by the covalent bond model

Answer 27

Group IVA

Question 28

Ion formation requires the presence of two elements:

Answer 28

a metal that can donate electrons and a nonmetal that can accept electrons

Question 29

The positive and negative ions simultaneously formed from such electron transfer attract one another, forming an

Answer 29

ionic compound

Question 30

a combination of Lewis symbols that represents either the transfer or sharing of electrons in chemical bonds

Answer 30

Lewis structure

Question 31

Ionic compounds are always

Answer 31

NEUTRAL note: The ratio in which positive and negative ions combine is the ratio that achieves charge neutrality for the resulting compound

Question 32

Formula Writing Rules for Ionic Compounds

Answer 32

1. The symbol for the positive ions is always written first 2. the charges on the ions that are present are not shown in the formula 3. The numbers in the formula (subscripts) give the combining ratio for the ions

Question 33

In the solid state, this compound consists of positive and negative ions in such a way that each ion is surrounded by nearest neighbors of the opposite charge

Answer 33

Ionic Compound

Question 34

Ionic compounds do not have ______molecules, only an alternating array of positive and negative ions

Answer 34

discreet

Question 35

represent the simplest combining ratio for the ions present

Answer 35

chemical formulas

Question 36

the smallest whole-number repeating ratio of ions present in an ionic compound that results in charge neutrality

Answer 36

formula unit

Question 37

The compounds NaCl, CO2, P4O10 are all what kind of compounds

Answer 37

binary compounds

Question 38

an ionic compound in which one element present is a metal and the other element present is a nonmetal

Answer 38

binary ionic compound

Question 39

Recognizing and Naming Binary Ionic Compounds: NAMING RULE:

Answer 39

the full name of the metallic element is given first, followed by a separate word containing the stem of the nonmetallic element and the suffix –ide. Ex. NaF - sodium fluoride

Question 40

Name the ff. binary ionic compounds: A.) MgO B. Al2S3 C. K3N D. CaCl2

Answer 40

Answers: a.) magnesium oxide b.) aluminum sulfide c.) potassium nitride d.) calcium chloride

Question 41

Naming Binary Compounds: metals and nonmetals

Answer 41

- So far, it has been assumed that the only behavior allowable for an element is that predicted by the octet rule - It is a good assumption for nonmetals and for most representative element metals - However, there are other metals that exhibit a less predictable behavior because they are able to form more than one type of ion. - For example, iron forms both Fe2+ and Fe3+ ions, depending on the chemical circumstances - When naming compounds that contain metals with variable ionic charges, the charge on the metal ion must be incorporated into the name. This is accomplished using Roman numerals

Question 42

Naming Binary Compounds: The chlorides of Fe2+ and Fe3+ (FeCl2 and FeCl3, respectively) are named

Answer 42

iron(II) chloride and iron(III) chloride

Question 43

Naming Binary Compounds: CuO is named

Answer 43

copper(II) oxide

Question 44

Naming Binary Compounds note

Answer 44

- If you are uncertain about the charge on the metal ion in an ionic compound, use the charge on the nonmetal ion (which does not vary) to calculate it - For example in CuO, you can note that the oxide ion carries a -2 charge (because oxygen is in group VIA), this means that the copper ion must have a +2 charge to counterbalance the -2 charge

Question 45

Naming Binary Compounds: how to calculate the metal ion charge

Answer 45

For example: AuCl 1. To calculate the metal ion charge, use the fact that the total ionic charge (both + and -) must add to zero (gold charge) + (chlorine charge) = 0 2. The chlorine has a -1 charge (group VIIA), therefore (gold charge) + (-1) = 0 3. Thus, Gold charge = +1 4. The name of the compound is gold(I) chloride

Question 46

Name the ff. binary ionic compound, each of which contains a metal whose ionic charge can vary: A. Fe2O3 B. PbO2 C. Cu2S

Answer 46

Answers: A. Iron(III) oxide B. Lead(IV) oxide C. Copper(I) sulfide

Question 47

Naming Binary Compounds: Fixed Charge

Answer 47

- You must know which metals exhibit variable ionic charge and which have a fixed ionic charge. - The fixed charge metals are those in group IA (+1 ionic charge), those in group IIA (+2 ionic charge) and five others (Al3+, Ga3+, Zn2+, Cd2+, and Ag+) - Metals from the diagram form ionic compounds without roman numerals in their names

Question 48

an ion formed from a single atom through loss or gain of electrons (Cl-, Na+, Ca2+)

Answer 48

Monoatomic ion

Question 49

an ion formed from a group of atoms (held together by covalent bonds) through loss or gain of electrons (SO42-)

Answer 49

Polyatomic ion

Question 50

This ion contains four O atoms and one S atom, and the whole group of five atoms has acquired a charge of -2

Answer 50

Polyatomic Ion

Question 51

form between atoms of dissimilar elements (metal + nonmetal)

Answer 51

Ionic bonds

Question 52

occurs between similar or even identical atoms (often two nonmetals are involved)

Answer 52

Covalent bond