Ionic, covalent bonding Flashcards
What type of atoms usually participate in ionic bonding
atoms of non metal and metal
what is the main characteristic of ionic bonding
a full outer shell
what is a giant ionic lactice
a repeating structure formed by ionic bonds consisting (P+N) ions
why do ionic compounds require a lot of energy to break their bond
because of the strong electrostatic attraction between ions
why do noble gases have a strong electrostatic configuration
(ionic bonding)
- they have a full outer shell
- they do not react easily or at all
- elements in other groups do not have full outer shells
electrostatic attraction meaning
force experienced by oppositely charged particles.
What are the properties of ionic bonding
high melting and boiling point
high solubility in water
low (solid) and high conductivity (molten)
why is there high melting/boiling points in ionic bonding
Strong electrostatic attractions between oppositely charged particles in all directions.
Requires a lot of energy needed to overcome strong attraction
High solubility in water in ionic bonding
Water molecules can break the electrostatic attraction between ions
conductivity in ionic bonding
solids ions have a low conductivity because they are in fixed positions
High conductivity as liquid/ gas ions are free to move
recap questions (ionic bonding)
- explain why the melting point of sodium chloride is high
- explain why sodium chloride can dissolve in water
- Why does sodium chloride have the formula NaCl and not NaCl2
- There are strong electrostatic attractions between the P+N ions, takes a lot of heat to overcome them
- The partial positive hydrogen atoms of water are attracted to the Cl⁻ ions, and the partial negative oxygen atoms are attracted to the Na⁺ ions, leading to dissociation
- because it represents a 1:1 ratio of sodium ions to chloride ions
Predict the formula of the following ionic compounds :
Potassium bromide
Lithium oxide
Calcium oxide
KBr
Li2O
CaO
strength of ionic bonds
bigger charge = stronger bond
smaller size = stronger bond
What type of atoms usually participate in covalent bonding
non-metals
How is a covalent bond formed
by sharing an electron between atoms
from which energy level do the electrons in covalent bonds come
outer energy level
what is a dative covalent bond
a bond where there is 1 pair of shared electrons between two atoms
what type of bond is formed when 2 pairs of electrons are shared
what type of bond if formed when 3 pairs of electron are shared
double bond
triple bond
bond strength and bond length
H-F vs H-Br
which is stronger
As the bond length increases – the bond strength decreases
The bond length of bromine is longer because it’s under fluorine in the periodic table. Flourine bond length is shorter.
Meaning, fluorine is stronger because the bond length is shorter
Which bond is stronger C=O or C-O? How do you know?
The first one is stronger because it is a double bond. It is shorter.
Tehedral shape of organic compounds
- Electrons position themselves as far away from each other as possible
properties of simple covalent bond and why?
LOW MELTING AND BOILING POINT
- covalent structures contain intermolecular forces. This is the force between molecules is weak so not much energy needed to melt
(they are usually gases in room temperature only few liquids)
DOES NOT CONDUCT ELECTRICITY
- no have a charge, remains neutral
- they can not move around, they are held in a covalent bond with a hydrogen atom
Giant covalent compounds
What are the allotropes of carbon
Diamond, graphite, jewellery and pencils
Giant covalent compounds
Diamond
- 4 strong covalent bonds per carbon
- High melting and boiling point - (requires lots of energy to break strong covalent bonds)
- Doesn’t conduct electricity - (no charged particles that can move)
Graphite
- 3 strong covalent bonds per carbon
- High melting and boiling point - (requires lots of energy to break strong covalent bonds)
- Conducts electricity
- Slippery - (weak intermolecular forces between layers which can slide over each other)
what type of atoms participate in metallic bonding
only metals
what are the properties of metallic bonding
- conducts electricity
Delocalised electrons that can move and carry the current - high melting and boiling points
Strong electrostatic attraction between delocalised electrons and (p) metal ions, require lots of energy to break - Malleable (bent into shapes)
Layers of ions which can slide over each other
what happens in metallic bonding
Metals lose electrons to become positive metal ions. (electrons are delocalised)
Why do metals conduct electricity
Has delocalised electrons that can move
what is a delocalised electron
An electron not in a shell around an atom, it is free to move throughout the structure
name some properties of metals
Conducts electricity, hard, dense, high melting point
