Unit 4: Chemical Bonding & Tetra Covalency of Carbon

Question 1

What characterizes ionic bonding?

Answer 1

Ionic bonding is formed between a metal and a nonmetal through the transfer of electrons.

Question 2

What is a pi bond and how is it formed?

Answer 2

A pi bond is formed between atoms already connected by a sigma bond.

Question 3

What is a chemical bond?

Answer 3

A mutual electrical attraction between the nuclei and valence electrons of different atoms.

Question 4

How is a covalent bond formed?

Answer 4

A covalent bond forms when two or more nonmetal atoms share electrons.

Question 5

What is the key difference in bond formation between sigma and pi bonds?

Answer 5

Sigma bonds are formed by axial overlap, while pi bonds are formed by sideways overlap of atomic orbitals.

Question 6

What defines a metallic bond?

Answer 6

A metallic bond is formed by the attraction between metal cations and delocalized electrons.

Question 7

What defines bond length in covalent bonds?

Answer 7

Bond length is the distance between bonded atoms at their minimum potential energy.

Question 8

What are valence electrons?

Answer 8

The outermost electrons of an atom available for losing, gaining, or sharing in chemical bonds.

Question 9

What is a sigma bond?

Answer 9

A sigma bond is formed by mutual overlap of atomic orbitals, characterized by maximum overlap.

Question 10

Why can’t a pi bond exist without a sigma bond?

Answer 10

A pi bond is an additional bond that requires a sigma bond to already be present.

Question 11

What is a hydrogen bond?

Answer 11

A hydrogen bond is an attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Question 12

What types of atoms form ionic bonds?

Answer 12

Ionic bonds are formed between a metal and a nonmetal.

Question 13

How are ionic bonds formed?

Answer 13

Through the transfer of valence electrons between a metal cation and a non-metal anion.

Question 14

How is bond energy expressed and what does it represent?

Answer 14

Bond energy is measured in kJ/mol and represents the energy needed to break a chemical bond.

Question 15

What is the impact of sigma bonds on atom rotation?

Answer 15

Sigma bonds allow free rotation of atoms around the bond axis.

Question 16

Which atoms commonly participate in hydrogen bonds?

Answer 16

Common atoms are oxygen, nitrogen, or fluorine, which carry a partial negative charge.

Question 17

What kind of orbitals overlap to form a hydrogen molecule?

Answer 17

A hydrogen molecule (H₂) is formed by the overlap of half-filled s-orbitals.

Question 18

How do non polar covalent bonds differ from polar covalent bonds?

Answer 18

Non polar bonds share electrons equally, while polar bonds do not.

Question 19

What defines a covalent bond?

Answer 19

A covalent bond is defined by the mutual sharing of electrons between two atoms.

Question 20

What are key properties of ionic bonds?

Answer 20

Ionic bonds are hard, with high melting and boiling points, and are brittle.

Question 21

What distinguishes the strength of sigma and pi bonds?

Answer 21

Sigma bonds are stronger due to significant overlap, whereas pi bonds are weaker due to less extensive overlap.

Question 22

What defines metallic bonding?

Answer 22

Metallic bonding involves the electrostatic attraction between positively charged ions and delocalized outer electrons.

Question 23

How is a pi bond formed?

Answer 23

A pi bond is formed by the sideways overlap of half-filled p-orbitals.

Question 24

What are the three types of covalent bonds based on shared electron pairs?

Answer 24

The three types are single, double, and triple covalent bonds.

Question 25

What are the characteristics of melting and boiling points in covalent compounds?

Answer 25

Covalent compounds typically have low melting and boiling points, often existing as liquids or gases at room temperature.

Question 26

What is electronegativity, and how does it trend in the periodic table?

Answer 26

Electronegativity measures electron attraction, increasing across a period and decreasing down a group.

Question 27

What is the definition of a molecule?

Answer 27

A group of covalently bonded atoms.

Question 28

How is a hydrogen molecule (H₂) formed?

Answer 28

A hydrogen molecule forms when two hydrogen atoms share electrons, creating a covalent bond.

Question 29

What is an example of ionic bonding involving sodium and chlorine?

Answer 29

Sodium (Na) loses one electron to chlorine (Cl), forming oppositely charged ions that create a crystal structure.

Question 30

What is the structure of a hydrogen atom?

Answer 30

Each hydrogen atom has one electron located in the 1s orbital.

Question 31

What distinguishes sigma bonds from pi bonds?

Answer 31

Sigma bonds involve head-on overlap and are stronger, while pi bonds involve lateral overlap.

Question 32

Why do covalent compounds not conduct electricity?

Answer 32

Covalent compounds do not conduct electricity in fused states or solutions due to lack of ions.

Question 33

What typically causes covalent bonding?

Answer 33

Covalent bonding occurs when elements share pairs of valence electrons, typically between non-metal elements.

Question 34

Why do atoms prefer to bond in terms of potential energy?

Answer 34

Atoms favor bonding as it results in lower potential energy.

Question 35

How do hydrogen atoms form a covalent bond?

Answer 35

Covalent bond formation occurs as overlapping electron clouds release energy between two approaching hydrogen atoms.

Question 36

What role does low ionization energy play in ionic bonding?

Answer 36

It allows an atom to readily lose electrons, facilitating the formation of cations necessary for ionic bonds.

Question 37

What defines the strength of sigma bonds?

Answer 37

Sigma bonds have maximum overlap, making them strong; all single bonds are classified as sigma bonds.

Question 38

What is Pauli's Exclusion Principle?

Answer 38

An orbital can hold a maximum of two electrons with opposite spins.

Question 39

What is the basis of valence bond theory in covalent bonding?

Answer 39

Covalent bonds form from overlapping half-filled atomic orbitals with electrons of opposite spins.

Question 40

How do different types of covalent bonds differ?

Answer 40

Single bonds share one pair, double bonds share two pairs, and triple bonds share three pairs of electrons.

Question 41

Why is high electron affinity important in ionic bonding?

Answer 41

High electron affinity helps an atom gain electrons easily, forming anions which are essential for ionic bonds.

Question 42

What determines the strength of a covalent bond?

Answer 42

The strength increases with larger overlap of atomic orbitals during bonding.

Question 43

What distinguishes a sigma bond from other covalent bonds?

Answer 43

A sigma bond is formed by head-on overlap and is the strongest type of covalent bond.

Question 44

How does lattice energy influence the strength of ionic bonds?

Answer 44

Higher lattice energy, resulting from strong electrostatic attractions, leads to stronger ionic bonds between ions.

Question 45

What factors influence lattice energy in ionic bonding?

Answer 45

The size and charge of ions; smaller size and higher charge increase lattice energy and bond strength.