Structure And Bonding Flashcards
Ionic bonding is
The electrostatic forces of attractions between oppositely charged ions
Why do compounds with giant ionic lattices have high melting and boiling points
- ESFOA between positive and negative ions
- very strong
- require large amounts of energy to overcome
- therefore have high melting and boiling points
Do ionic compounds conduct electricity
Not when solid, only when molten or in aqueous solution
Covalent bonding is
The electrostatic forces of attraction between nuclei and shared pairs of electrons
Why substances with a simple molecular structure are gases or liquids, or solids with low melting and boiling points
- weak intermolecular forces between molecules
- require little energy to overcome
- low melting/boiling points therefore liquids/gases
Do covalent compounds conduct electricity
- no
- molecules have no mobile charged particles to carry current
Why diamonds is strong with a high melting point
- giant covalent lattice
- 4 covalent bonds per C
- very strong
- require large amount of energy to overcome
therefore high melting point
Why does diamond not conduct electricity
- no charged particles that are mobile
- cannot carry charge
Why graphite is useful in pencil lead
- giant covalent structure in layers
- weak attraction between layers
- require little energy to overcome
- can slide over each other and deposit on paper
Why graphite has a high melting point
- giant covalent structure
- 3 covalent bonds per atom
- very strong
- requires large amounts of energy to overcome therefore high melting point
Why does graphite conduct electricity
- giant covalent structure in layers
- 3 covalent bonds per atoms leaves one delocalised
- can carry current
Fullerenes have low melting/boiling points and can’t conduct electrons. Why?
- molecules
- weak intermolecular forces between molecules
- require little energy to overcome
Metallic bonding is
The electrostatic forces of attraction between metal cations and delocalised electrons
Why are metals malleable
The metal ions slide over eachother and settle in a new position
Why are metals tough solids with high melting points
- esfoa between metal cations and delocalised electrons
- strong
- require a lot of energy to overcome
Why metals are good conductors of electricity
- delocalised electrons in metallic lattice
- can move and conduct electricity
what are ions
Ions are electrically charged particles formed when atoms lose or gain electrons
Charge of Ag
+
Charge of Cu
2+
Charges of Fe
2+, 3+
Charge of Pb (lead)
2+
Charge of Zn
2+
Hydroxide charge
OH-
Hydrogen charge
H+
Ammonium charge
NH4 +
Carbonate charge
CO3 2+
Nitrate charge
NO3 -
Sulfate charge
SO4 2-
How is a covalent bond formed
two non-metal atoms by sharing a pair of electrons in order to fill the outer shell
explain why the melting and boiling points of substances with simple molecular structures increase with increasing relative molecular mass
- larger molecules (molecules with more mass) have more forces of attraction between them
- these forces, although weak, must be overcome if the substance is to boil, and larger molecules have more attractions which must be overcome.
Metals have a regular arrangement of
layers of positive ions surrounded by a sea of delocalised electrons.
