chemical bonding Flashcards
types of chemical bonding
- ionic
- covalent
- metallic
what is ionic bonding
the mutual electrostatic attraction between ions of opposite charges
how to name ionic compounds
- cation first
- anion second
how to find the name of an ion
the element name + ‘ide’ (e.g. chlorine ion = chloride)
(oxygen atom present, _ate)
what is the formulae to find ionic compounds
cross multiply
what is important when drawing the ions (with different charge) of ionic compounds
put the number infront of the ion that does not have enough to cancel out the other ion
(e.g. 2[ion drawing]
polyatomic ions
- hydroxide ion
- nitrate ion
- sulfate ion
- carbonate ion
- phosphate ion
- ammonium ion
chemical formula for hydroxide ion
OH⁻
chemical formula for nitrate ion
NO₃⁻
chemical formula for sulfate ion
SO₄⁻
chemical formula for carbonate ion
CO₃⁻
chemical formula for phosphate ion
PO₄⁻
chemical formula for ammonium ion
NH₄⁺
transition metals
- iron
- copper
- zinc (Zn²⁺)
- silver (Ag⁺)
ionic bonding forms
giant ionic crystal lattice structure at room temperature
what does the giant ionic crystal lattice structure consists of
large numbers of alternating positive and negative ions held together by strong electrostatic forces
physical properties of ionic substances
- high melting and boiling point
- hard but brittle
- soluble in water
- insoluble in organic solvents
- can conduct electricity
how to identify melting and boiling point
- type of forces of attraction
- strength of force
- amount of energy required to overcome
what is required for electrical conductivity
presence of mobile ions or free-moving electrons
what states can conduct electricity
- liquid
- aqueous
what affects the melting point of an ionic compound
ionic bond
stronger ionic bond…
higher melting point
what is covalent bonding
atoms share electrons to obtain noble gas electronic configuration
what elements can be bonded using covalent bonding
non metal + non metal
what is an electron pair
2 electrons that are shared between 2 atoms
what is a covalent bond
electron pair
number of electrons needed =
number of electrons shared
steps to draw covalent bonding
- electronic configuration
- calculate number of electrons needed
- draw number of electrons shared in the overlapping area
- fill in remaining electrons
how to name covalent bonds
(no.) _ (no.) _ide
name for numbers (1-5)
- 1: mon
- 2 : di
- 3 : tri
- 4 : tetra
- 5 : penta
physical properties of simple covalent substances
- atoms are held together by strong covalent bond
- molecules held together by weak intermolecular forces of attration
- low melting boiling point
- soluble in organic solvent
- insoluble in water
- unable to conduct electricity
larger molecules …
higher melting and boiling points
why cant covalent compounds conduct electricity
- absence of mobile charge carriers
- no ions
- no free moving electrons since it has been shared
what are giant covalent structures
atoms are connected to one another via strong covalent bonds
examples of giant covalent structures
- diamond
- graphite
- silica / silicon dioxide
properties of diamond
- 1C : 4C
- strong covalent bonds
- tetrahedral arrangement
properties of graphite
- 1C : 3C
- hexagonal rings arrangement
- strong covalent within each layer
- weak intermolecular forces of attraction between the layer
- delocalised electrons between layer
- can conduct electricity
- layers can slide past one another
properties of silicon dioxide
- 1 Si : 2O
- made up of silicon and oxygen ions
- strong covalent bonds
- tetragedral arrangement
metallic bonding
the bond between metal cations and delocalised electrons
what do metallic bonds form
giant metallic latice structure
properties of metallic bonds
- high mp, bp
- strong electrostatic forces of attration between metal cations and sea of delocalised electrons
- large amounts of energy required to overcome forces of attraction
- insoluble in water and organic solvent
- good conductor of electricity
physical properties of metallic bonds
- malleable
- ductile
- sonorous
- good conductor of electricity and heat
what are alloys
mixture that consists of at least 1 metal
properties of alloys
-
types of alloys
- bronze
- steel
properties of bronze
made up of about 90% copper, 10% tin
structural properties of pure metals
- regular structure
- if enough force is applies, the layers of metal cations can slide over one another easily, over a sea of delocalised electrons
- malleable
- ductile
structural properties of alloys
- regular lattice arrangement is disrupted by the particles of a different size
- a larger force is needed to make the layers slide over each other
- less malleable and ductile
