Structure and Bonding Flashcards
Isotopes
same number of protons, different number of neutrons (and therefore different atomic mass number)
Atom
Atoms are composed of electrons and a nucleus. The nucleus contains protons and neutrons.
Element
When a substance contains only one type of atom, it is called an element.
Ions
an atom or molecule with a charge due to the loss or gain of one or more electrons
Electronegativity
a measure of an atom’s ability to attract shared electrons
Periods
horizontal rows on the periodic table (number of electron shells in an atom of that element).
Groups
vertical columns on the periodic table (number of valence electrons in the valence/outer electron shell - exception transition metals).
Atomic Radii
the total distance from an atom’s nucleus to the outermost orbital of electron (decreases down a period and increases down a group)
Ionic Bonding
The strong electrostatic force of attraction between positively and negatively charged ions.
Monatomic ions
Ion formed from a single atom i.e Cl–> Cl-
Polyatomic ions
A group of atoms covalently bonded together, but the group of atoms as a whole has a charge.
Ionic Property: Hardness
Structure: Giant Ionic Lattice
Bonding: Strong electrostatic force of attraction between oppositely charged ions which requires a lot of force to break
Ionic Property: High MP/BP
Structure: Giant Ionic Lattice
Bonding: Strong electrostatic force of attraction between oppositely charged ions which requires a lot of energy to break
Ionic Property: Brittle
Structure: Giant Ionic Lattice
Bonding: Lattice arrangement of ions that, when a strong enough force is applied, the lattice may shift and like charges align and repel. This breaks the lattice.
Ionic Property: Conductivity
Structure: Giant Ionic Lattice
Bonding: To conduct electricity, there needs to be a flow of charged particles (ions). As a solid, ions are not free to move and carry charge whereas as a liquid/molten the ions are free to move and carry charge.
Chemical Equations
Format: REACTANTS –> PRODUCTS
Aqueous state symbol
Dissolved in water (Aq)
Solid state symbol
(s)
Liquid state symbol
(l)
Gas state symbol
(g)
Sulfate ion
SO4 (2-)
Carbonate ion
CO3 (2-)
Alloy
Mixtures of two or more metal elements
Common properties of metals
Melting Points
Boiling Points
Lustre
Malleability
Ductile
Heat conductivity
Electrical conductivity
Metallic bonding
Metallic bonding is the electrostatic attraction between cations and their delocalized valence electrons.
Metallic structure
Giant metallic lattice
Metallic Property: High MP/BP
Structure: Giant metallic lattice
Bonding: strong electrostatic forces of attraction between cations and the sea of delocalized electrons which require a lot of energy to break
Metallic Property: Lustre
Structure: Giant metallic lattice
Bonding: a sea of delocalized electrons exist within the lattice that are able to reflect light
What does malleable mean?
Able to be changed shape (into thin sheets)
Metallic Property: Malleable & Ductile
Structure: Giant metallic lattice
Bonding: strong electrostatic forces of attraction between cations and the sea of delocalized electrons which means the shape can be changed without the forces being broken
What does ductile mean?
Ability to be shaped into thin wires
Metallic property: Heat conductivity
Structure: Giant metallic lattice
Bonding: Kinetic energy of cations (vibrations) and electrons (movement) is passed efficiently through the metal
Metallic property: Electrical conductivity
Structure: Giant metallic lattice
Bonding: Delocalized valence electrons are free to move and carry a charge.
Displacement reaction
a more reactive element takes the place of a less reactive element in a salt.
METAL + DILUTE ACID –>
SALT + HYDROGEN
METAL + OXYGEN –>
METAL OXIDE
METAL + WATER –>
METAL HYDROXIDE + HYDROGEN
METAL + STEAM –>
METAL OXIDE + HYDROGEN
Electronegativity
The tendency in which atoms or molecules pull electrons towards itself.
Polar
Uneven distribution of electrons
Giant Covalent Lattice
3-dimensional structure arising from atoms forming many covalent bonds.
Examples of giant covalent lattice structures
Graphite and diamond
Giant Cov. Property: Hardness (Diamond)
Structure: Giant Covalent Lattice
Bonding: Many covalent bonds within the structure which can withstand significant force
Giant Cov. Property: Softness (Graphite)
Structure: Giant Covalent Lattice
Bonding: Layers of carbon sheets with delocalised electrons between the layers. These sheets can slide over each other easily.
Giant Cov. Property: Electrical Conductivity (Graphite)
Structure: Giant Covalent Lattice
Bonding: Layers of carbon sheets with delocalised electrons between the layers. These delocalised electrons can move and carry charge.
Giant Cov. Property: Conductivity (Graphite)
Structure: Giant Covalent Lattice
Bonding: Diamond does not contain any free moving charged particles and so cannot conduct electricity.
Intramolecular
Forces within molecules/compounds.
Examples of intramolecular forces
- Ionic Bonding
- Metallic Bonding
- Covalent Bonding
Intermolecular
forces found between simple covalent molecules.
Examples of intermolecular forces
- Dispersion forces
- Dipole-dipole forces
- Hydrogen bonds
Dispersion forces (temporary)
Occur between all molecules and atoms due to the constant movement of electrons
Dipole-Dipole forces (permanent)
Attraction between polar simple covalent molecules.
Hydrogen bond
“extra-strong” dipole-dipole attraction between H-NOF of one molecule and NOF of a neighbouring molecule
Solute
the substance being dissolved
Solvent
is the primary component of the solution. It does the dissolving.
Solution
an evenly distributed mixture of atoms, molecules and/or ions including a liquid solvent and one or more solutes.
Precipitate
is an insoluble salt formed from two aqueous reagents.
Spectator Ions
ions not involved in a chemical reaction that remain in solution
What does the term ‘giant’ mean when talking about a structure?
An unlimited/undefined number of particles in the structure.
What does the term ‘lattice’ mean when talking about a structure?
A regular, repeating 3-dimensional arrangement
Covalent Bonding
The electrostatic force of attraction between two atomic nuclei and a shared pair of valence electrons between those atoms
Covalent Molecular Property: Low MP/BP
Structure: Simple covalent molecular
Bonding: Weak intermolecular forces exist between molecules which do not require a lot of energy to overcome
Covalent Molecular Property: Does not conduct electricity
Structure: Simple covalent molecular
Test for metal cations
Flame test
Ca2+ ion flame colour
Brick Red
K+ ion flame colour
Purple
Na+ ion flame colour
Orange
Li+ ion flame colour
Red
Describe the test for ammonia
add 3 drops of dilute sodium hydroxide solution
gently heat
if NH4+ is present - characteristic choking smell produced. The ammonia fumes turn damp red litmus paper or damp universal indicator paper from red to blue.
Describe the test for carbonate ions
add 3 drops of dilute hydrochloric acid
bubble gas through limewater
if CO32- present, limewater turns cloudy
Describe the test for sulfate ions
add 3 drops of dilute hydrochloric acid
add 3-4 drops of barium chloride solution
if SO42- present a white precipitate forms
Describe the test for halide ions
Add 3 drops of dilute nitric acid
then add 3-4 drops of silver nitrate solution
Colour change when chloride ions are present
White
Colour change when bromide ions are present
Cream
Colour change when iodide ions are present
Yellow