bonding

Question 1

What is ionic bonding?

Answer 1

Bonding between metals and non-metals where electrons are transferred from metal to non-metal, forming positive and negative ions.

Question 2

What forms as a result of ionic bonding?

Answer 2

Ionic compounds exist as a giant ionic lattice structure.

Question 3

What is the charge of metal and non-metal ions in ionic bonding?

Answer 3

Metal forms positive ions, while non-metal forms negative ions.

Question 4

What is the electrostatic force of attraction?

Answer 4

The attraction between oppositely charged ions in ionic compounds.

Question 5

What determines the strength of ionic bonding?

Answer 5

Atomic radius and charge on ions.

Question 6

How does atomic radius affect ionic bonding strength?

Answer 6

Smaller ions lead to stronger ionic bonding due to closer packing in a lattice.

Question 7

What happens to ionic bonding strength down a group?

Answer 7

Ionic bonding becomes weaker due to larger ions with more shells and increased shielding.

Question 8

What is a covalent bond?

Answer 8

A shared pair of electrons between two non-metals.

Question 9

What type of diagrams can represent covalent bonds?

Answer 9

Stick diagrams and dot and cross diagrams.

Question 10

What is a coordinate (dative) covalent bond?

Answer 10

A bond where one atom provides both electrons.

Question 11

What are simple molecules?

Answer 11

Molecules consisting of two or more atoms bonded together, e.g., Cl2, H2O.

Question 12

What are giant covalent structures?

Answer 12

Large networks of covalently bonded atoms, such as diamond and graphite.

Question 13

What is the structure of diamond?

Answer 13

Tetrahedral shape with each carbon bonded to four others.

Question 14

What are the physical properties of diamond?

Answer 14

Hard, good thermal conductor, insoluble in water.

Question 15

What is the structure of graphite?

Answer 15

Consists of sheets of hexagonal layers with each carbon bonded to three others.

Question 16

How does graphite conduct electricity?

Answer 16

Due to delocalised electrons that can move and carry charge.

Question 17

What is metallic bonding?

Answer 17

Attraction between positive metal ions and delocalised electrons.

Question 18

What is the structure of metals?

Answer 18

Giant lattice structures with closely packed positive ions and delocalised electrons.

Question 19

What characterizes solids in terms of particle arrangement?

Answer 19

Particles are close together, giving high density and incompressibility.

Question 20

What is required to change the state of a substance?

Answer 20

Energy in the form of heat to break the forces holding particles together.

Question 21

What determines the melting/boiling points of ionic compounds?

Answer 21

High due to strong electrostatic forces.

Question 22

What defines the conductivity of ionic compounds?

Answer 22

Conductive when molten or dissolved due to free-moving ions.

Question 23

What is electronegativity?

Answer 23

The power of an atom to attract electron density in a covalent bond.

Question 24

How does atomic radius affect electronegativity?

Answer 24

Smaller atomic radius leads to higher electronegativity.

Question 25

What is the trend of electronegativity across a period?

Answer 25

Increases due to decreasing atomic radius and constant shielding.

Question 26

What is the difference between polar and non-polar covalent bonds?

Answer 26

Polar bonds have unequal sharing of electrons; non-polar bonds have equal sharing.

Question 27

What are intermolecular forces?

Answer 27

Forces of attraction between molecules, much weaker than covalent, ionic, and metallic bonds.

Question 28

What is Van der Waals force?

Answer 28

Induced dipole-dipole attraction due to uneven electron distribution.

Question 29

What is the main characteristic of giant covalent structures?

Answer 29

They have very high melting and boiling points due to strong covalent bonds.

Question 30

What is the shape and bond angle of a linear molecule?

Answer 30

Linear shape with a bond angle of 180 degrees.

Question 31

What is the bond angle in a tetrahedral molecule?

Answer 31

109.5 degrees.

Question 32

What occurs in a trigonal planar molecule?

Answer 32

Bond angles of 120 degrees with three bonding pairs and no lone pairs.

Question 33

What happens when a molecule has polar bonds but is symmetrical?

Answer 33

The molecule is non-polar as the dipoles cancel out.

Question 34

What is the role of lone pairs in determining molecular shape?

Answer 34

Lone pairs repel more than bonding pairs, affecting the geometry.

Question 35

What causes an uneven distribution of electrons?

Answer 35

The constant movement of electrons causes an uneven distribution of electrons. ## Footnote This results in the formation of temporary dipoles.

Question 36

What is a temporary dipole?

Answer 36

A temporary dipole is an induced dipole in a neighboring molecule due to electron density variations. ## Footnote This results in attractions between delta + and - charges.

Question 37

How does the size of a molecule affect van der Waals forces?

Answer 37

Bigger molecules have more electrons, leading to greater van der Waals forces and higher boiling points. ## Footnote This is why boiling points increase down a group and with longer hydrocarbons.

Question 38

What type of attraction occurs in polar molecules?

Answer 38

Permanent dipole-dipole attraction occurs in polar molecules. ## Footnote This is not present in non-polar molecules, even if they have dipole bonds.

Question 39

What are the characteristics of permanent dipole-dipole attractions?

Answer 39

Weak electrostatic forces of attraction between delta + and - charges of adjacent molecules. ## Footnote These attractions lead to higher boiling points compared to induced dipole-dipole attractions.

Question 40

What is the strongest intermolecular force?

Answer 40

Hydrogen bonding is the strongest intermolecular force. ## Footnote It occurs when hydrogen is bonded to fluorine, oxygen, or nitrogen.

Question 41

How does hydrogen bonding affect the charge density of hydrogen?

Answer 41

Hydrogen has a high charge density due to being small and having only one electron in use in the bond. ## Footnote This high charge density allows hydrogen to attract lone pairs of electrons on F, O, or N in neighboring molecules.

Question 42

What is the significance of hydrogen bonding in ice?

Answer 42

Hydrogen bonding is important for the structure and density of ice. ## Footnote It holds molecules in a fixed position when frozen, resulting in ice being less dense than water.

Question 43

Why does ice float on water?

Answer 43

Ice is less dense than water because the hydrogen bonds hold water molecules in a less tightly packed structure. ## Footnote This allows for life to exist beneath icy surfaces, acting as an insulator.

Question 44

Which compounds have the highest boiling points among their group?

Answer 44

H2O, HF, and NH3 have the highest boiling points due to hydrogen bonding. ## Footnote H2O can form 4 hydrogen bonds, while HF and NH3 can only form 2.

Question 45

What trend is observed in boiling points down a group?

Answer 45

Boiling points generally increase down a group due to more electrons and increased van der Waals forces. ## Footnote Group 4 hydrides have the lowest boiling points due to being nonpolar and having only van der Waals attractions.

Question 46

What types of bonds do Group 5, 6, and 7 hydrides exhibit?

Answer 46

Group 5, 6, and 7 hydrides exhibit permanent dipole-dipole or hydrogen bonds, which are stronger. ## Footnote These bonds contribute to higher boiling points compared to Group 4 hydrides.