Bonding 3.1- 3.2

Question 1

Is bonding an empirical or theoretical concept?

Answer 1

Bonding is one of the most theoretical concepts in chemistry. We do not have direct visible evidence for bonds between atoms.

Question 2

What did Friedrich Kekule illustrate about bonding theory?

Answer 2

In 1858, Friedrich Kekule illustrated a structural formula, representing a bond as a dash between bonding atoms.

Question 3

What did Edward Frankland suggest about bonding theory?

Answer 3

In 1852 Edward Frankland stated that every element has a fixed bonding capacity.

Question 4

What did Jacobus van’t Hoff and Joseph Le Bel contribute to bonding theory?

Answer 4

In 1874, they independently extended structural formula to 3 dimensions. They revised the theory to explain the ability of certain substances to change light as as it passes through the substance.

Question 5

What did Richard Abegg Explain about bonding theory? Which scientist discovered evidence that supported Abegg’s ideas?

Answer 5

In 1904, he was the first to suggest that bonding capacity is related to an atom’s electron structure. Rutherford’s evidence for a nuclear atom supported this. Abegg also suggested the stability of the noble gasses was due to the number of electrons.

Question 6

What did Gilbert Lewis contribute to bonding theory?

Answer 6

In 1916, he combined evidence of chemical formulas, the concept of valence, and the concept of stable electron numbers for atoms. Said that atoms could have stable electron numbers by sharing them or transferring them. This can only happen if the atoms are close which would result in an attractive force- covalent bond.

Question 7

Valence Electron

Answer 7

Electrons in the highest energy level of an atom.

Question 8

Ionic bond

Answer 8

Simultaneous attraction between positive and negative ions resulting from the transfer of one or more valence electrons.

Question 9

Covalent bond

Answer 9

Simultaneous attraction of the nuclei of two atoms for valence electrons that they share between them.

Question 10

How are electrons described in quantum mechanics?

Answer 10

Electrons are described in terms of their energy content, and orbitals in terms of calculated probability of an electron being at any given point relative to the atomic nucleus.

Question 11

Orbital

Answer 11

A specific volume of space in which an electron of a certain energy level is likely to be found. Each orbital may contain two, one, or no electrons.

Question 12

Bonding electron

Answer 12

An atom with a valence orbital that is occupied by one electron can theoretically share this electron with another atom.

Question 13

Lone pair

Answer 13

Two electrons occupying the same orbital. This has a repelling effect on any nearby orbitals.

Question 14

How many orbitals can be in the first energy level of an atom?

Answer 14

One orbital with a maximum of two electrons.

Question 15

What element has unique properties and why?

Answer 15

Hydrogen is the smallest reactive atom with the simplest structure and only one energy level. This is why it is unique and is an exception to most rules and generalizations.

Question 16

Energy levels above the first contain this many orbitals.

Answer 16

Four orbitals, maximum eight electrons.

Question 17

Octet rule

Answer 17

A structure with eight electrons filling a valence level is very stable. The rule is usually obeyed by main group atoms but only C, N, O, F atoms always obey the rule when bonding.

Question 18

The Pauli exclusion principle

Answer 18

Two electrons may share the same region of space at the same time (orbitals may have 0, 1, or 2 electrons).

Question 19

Electronegativity

Answer 19

Relative ability of an atom to attract a pair of bonding electrons in its valence level.

Question 20

Crystal Lattice

Answer 20

Ions in an ionic compound always pack together to form a repeating 3D pattern. This is called a crystal lattice because when the ions assemble , the structure is always crystalline.

Question 21

A type of bonding where no chemical reaction occurs.

Answer 21

Metallic bonding

Question 22

Why does chlorine exist as diatomic molecules

Answer 22

Chlorine has 7 valence electron and only requires one to obtain a stable octet. By sharing a pair of electrons, two chlorine atoms can achieve stability.

Question 23

Molecular Element

Answer 23

Chemical species that has at least two atoms of the same element bonded to each other.

Question 24

Double bond

Answer 24

When atoms share two pairs of electrons in a chemical bond.

Question 25

Bonding capacity

Answer 25

The maximum number of single covalent bonds that an atom can form. It is determined by its number of bonding electrons

Question 26

Coordinate covalant bond

Answer 26

An atom overlaps a full valence orbital (lone pair) with an unoccupied one

Question 27

Ionic compound formula

Answer 27

Empirical formulas representing the crystal lattice with a ratio showing the simplest number of cations to anions.

Question 28

Empirical formula

Answer 28

Shows the simplest ratio of atoms in the compound. Rarely useful for molecular compounds

Question 29

Molecular formula

Answer 29

Shows the actual number of atoms that are covalently bonded to make up each molecule

Question 30

Lewis formula

Answer 30

Uses Lewis symbols to show electron sharing in covalent bonds, and the formation of stable valence octets in molecules and ions

Question 31

Structural formula

Answer 31

Shows which atoms are bonded and represents the type of covalent bond with the number of lines drawn between atomic symbols

Question 32

Stereochemical formula

Answer 32

A structural formula drawn to try and represent the 3-D molecular shape

Question 33

Central atom

Answer 33

Atom to which ll other (peripheral) atoms are bonded.

Question 34

What did Dr. Linus Pauling explain

Answer 34

In 1939 he explained why certain electron arrangements are stable as well as showing that electron sharing must cover a complete range from equal attraction to total transfer. In 1954 Dr. Pauling won the Nobel prize.

Question 35

Timeline of the old dudes

Answer 35

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