Bonding AS Flashcards
When are ions more stable
When they are they are closer to oppositely charged ions.
What is the strength of attraction between oppositely charged particles based on
Distance between particles (shorter distance =stronger attraction therefore stronger IB)
Distance also relate to the size of the ions radius (smaller the radius the shorter the distance between ions and stronger attraction therefore stronger IB)
Size of charge each particle has (Greater charge = stronger attraction - stronger IB)
groups of ions arrange themselves to
To minimise distance between opposite charges (maximise attraction)
Maximise distance between like charges (minimise repulsion)
How are ions arranged
They are arranged in a 3D lattice structure (called giant ionic lattice)
Why do ionic compounds have a high melting point
Large amounts of energy are needed to break lattice apart
How is a covalent bond formed
The positively charged nuclei will be attracted to the increase in electron density between the atoms pulling them inward and closer together.
Orbitals overlap / merge forming a new orbital called bonding/ molecular orbital
He electrons can exist anywhere within the new orbital
Both atoms have “access” to electrons in this orbital
So they can achieve a full outer shell
What is the distance between 2 nuclei called
Bond length
Definition of a covalent bond
Attraction of a positively charged nucleus to a shared pair of electrons
Why are double bonds stronger than single bonds
Due to the different shapes and directions of p orbitals . (BUT the second bond (pi) isn’t as strong as the first bond (sigma) therefore meaning a double bond isn’t twice as strong as a single bond.
Have both types of bond sigma and pi.
What is a sigma bond
When orbitals overlap easily and and directly
Why is a sigma bond very strong
The nuclei both have high level of attraction to the electrons in the orbital making the sigma bond strong.
What are double bonds always
What are single bonds always
Double bonds = pi bonds (also have sigma bonds)
Single bonds = sigma bonds
Why are pi bonds weaker that sigma bonds
P orbitals bend sideways creating 2 areas of electron density above and below sigma bond. Electrons in this orbital are further from the nucleus therefore meaning less attraction and weaker bond.
What is meant by the term lone pair
Refers to electron pair in the outer orbital of an atom that isn’t involved in bonding .
What is a coordinate/ dative covalent bond
a covalent bond (a shared pair of electrons) in which both electrons come from the same atom.
How can we represent a coordinate/ dative covalent bond
With a arrow pointing towards the thing that is receiving the donated electrons.
What are temporary induced dipole dipole(wan de waals) forces
Type of intermolecular force
Exist between ALL MOLECULES
Weakest type of intemolecular force
How are temporary induced dipole dipole (wan Der waals) forces formed
The electrons in a covalent bond between two atoms are always moving randomly and may not be equally distributed or shared between them.
This causes one of the atoms to have a partial negative charge and one of the atoms to have a partial positive charge (creates a dipole)
Dipole from one molecule can induce a dipole from another molecule if a delta - is next to a delta+ then it creates a point of attraction between them.
This lasts for a VERY short period of time
How can we tell if a molecule is non-polar?
Molecule will be nonpolar if
1) The molecular shape around the central atom has no lone pairs, or if it does it’s either square planar or linear
2) All atoms around the central atom are the same
How do van der waals forces occur
Uneven distribution of electrons in one molecule induces dipole in neighbouring/another/nearby molecule
What is metallic bonding?
Metallic bonding is the electrostatic attraction between positively charged metal ions and delocalized electrons.
True or False: In metallic bonding, electrons are localized around individual atoms.
False
What are the characteristics of metals due to metallic bonding?
Metals are typically good conductors of electricity and heat, malleable, ductile, and have a high melting point.
Fill in the blank: In metallic bonding, electrons are described as __________.
delocalized
Which model is used to describe metallic bonding?
The sea of electrons model.
What role do delocalized electrons play in metallic bonding?
They allow for the conduction of electricity and contribute to the malleability and ductility of metals.
Which property of metals is primarily due to metallic bonding?
Malleability
True or False: Metallic bonds are stronger than ionic bonds.
False
What is the effect of increasing the number of delocalized electrons on metallic bonding strength?
The strength of metallic bonding increases with more delocalized electrons.
List two examples of metals that exhibit metallic bonding.
Copper and aluminum.
What is the relationship between the structure of metals and their properties?
The regular arrangement of metal ions and the presence of delocalized electrons results in high electrical and thermal conductivity.
Fill in the blank: The __________ the metallic bond, the higher the melting point of the metal.
stronger
What is an alloy?
An alloy is a mixture of two or more elements, where at least one is a metal.
How does the presence of different elements in an alloy affect its properties?
Alloying can enhance strength, corrosion resistance, and other properties compared to pure metals.
True or False: All metals have the same type of metallic bonding.
True
What are the factors that influence the strength of metallic bonds?
The charge of the metal ions and the number of delocalized electrons.
Multiple Choice: Which of the following is NOT a characteristic of metallic bonding? A) Ductility B) High melting point C) Brittle C) Electrical conductivity
C) Brittle
What type of structure do metals typically form?
Metallic lattice structure.
Fill in the blank: The __________ model helps explain why metals are good conductors of electricity.
sea of electrons
How does metallic bonding contribute to the ductility of metals?
The layers of metal ions can slide over each other without breaking the metallic bond due to the delocalized electrons.
What happens to the metallic bond when a metal is heated?
The metallic bond remains intact, but the increased kinetic energy allows atoms to vibrate more, which can lead to melting.
True or False: The strength of metallic bonds is the same in all metals.
False
What is the significance of the term ‘electropositive’ in relation to metals?
Electropositive refers to the tendency of metal atoms to lose electrons and form positive ions.
Why do metals tend to have high densities?
Metals have closely packed ions in a metallic lattice, contributing to their high density.
What is the effect of impurities on metallic bonding?
Impurities can disrupt the regular arrangement of metal ions, affecting the properties of the metal.
Multiple Choice: Which property is NOT typically associated with metals? A) Conductivity B) Malleability C) Insulating D) Ductility
C) Insulating
