Chemical Bonding Flashcards
Pure Substances:
Cannot be separated into smaller parts. They are either elements or compounds.
Element:
Contains only one type of substance that cannot be separated by chemical or physical means. Can be metals, non-metals, or transition elements.
Compound:
Made of two or more elements chemically combined. Can be separated by chemical means. They are molecular or ionic compounds.
Two or more elements together make a ________.
molecule
How many atoms are present in C12H26?
38
How many atoms are present in Ca3(PO4)2?
11
What does the atomic number represent?
The number of protons and electrons in the atom.
What does the atomic mass represent?
The number of protons and neutrons.
How do you find the number of protons?
Equal to the atomic number.
How do you find the number of electrons in an atom?
Equal to the atomic number.
How do you find the number of neutrons?
Atomic mass - the atomic number.
Monoatomic ions:
Single atoms that have gained or lost electrons.
Cations:
Positively charged. Use the full name with “ion” at the end.
Anions:
Negatively charged. Change the suffix to “___ide” and add ion.
Name P^3-
Phosphoride ion.
Name Zn^2+
Zinc ion.
If F becomes F^-, were electrons gained or lost?
Gained.
If Ba becomes Ba^2+, were electrons gained or lost?
Lost.
Multi-valent ions:
Have more than one possible charge.
Polyatomic ions:
When two or more atoms are so closely bound, they act like one unit.
Alkali metals:
Group 1. Highly reactive, soft, shiny, silver.
Alkaline earth metals:
Group 2. Not the softest or most reactive. Shiny and silver.
Halogens:
Group 17. Poisonous and react with alkali metals to form salts.
Noble gases:
Group 18. Very stable.
Metals are (more/less) reactive as you move down a group.
more
Non-metals are (more/less) reactive as you move down a group.
less
Characteristics of metals:
Conduct heat and electricity, solid at room temperature (except mercury), form cations by losing electrons.
Characteristics of non-metals:
Poor conductors, are a variety of colours, occur as solid liquid or gas at room temperature, form anions by gaining electrons.
Ionic compounds:
A metal and nonmetal combined. Electrons are transferred. Solid at room temperature, conduct electricity in liquid or aqueous form.
Molecular compounds:
Two non-metals that share electrons. Any state at room temperature. Do not conduct electricity in liquid and aqueous form.
Diatomic molecules:
H, N, F, O, I, Cl, Br
Polyatomic molecules:
P4, S8
Name the ionic compound: Ag2S
Silver sulphide
Name the ionic compound: Na2O
Sodium oxide
Name the ionic compound: Sodium sulphide
Na2S
Name the ionic compound: Calcium nitride
Ca3N2
Name this multivalent compound: iron (III) oxide
Fe2O3
Name this multivalent compound: PbO2
Lead (IV) oxide
Is this ionic compound aqueous or solid in solution? CaSO4
Solid
Is this ionic compound aqueous or solid in solution? FeCl3
Aqueous
Intramolecular:
Bonds between atoms within the molecule.
Intermolecular:
When atoms, ions, or molecules bond together to form relatively large lumps of matter.
Electronegativity:
The ability to attract electrons.
Put these atoms in order of electronegativity from smallest to largest: Ti, Mn, Se, K, Br, Sn
K, Ti, Mn, Sn, Se, Br
What is the electronegativity for ionic bonds?
A difference of 1.7 or more.
What is the electronegativity for polar covalent bonds?
A difference of less than 1.7. (0.4-1.7)
What is the electronegativity for covalent bonds?
No difference. (0-0.4)
What type of electronegativity bond is this? C-C
Covalent
What type of electronegativity bond is this? H-F
Ionic
What type of electronegativity bond is this? H-O
Polar
Ionic compounds form _______ ________.
crystal lattices
Crystal lattices are _____ at room temperature.
solid
Crystal lattices are most commonly _____ in colour.
white
True or False: Crystal lattices have very strong bonds.
True.
True or false: Crystal lattices have low melting points.
False.
How are crystal lattices arranged?
In repeating 3D shapes.
Are crystal lattices typically soluble in water, why?
Yes because water is polar and the cations are attracted to the oxygen while the anions are attracted to the hydrogen.
Most molecular compounds have (low/high) melting and boiling points.
low
Name this molecular compound: P2O5
Diphosphorus pentoxide
Name this molecular compound: Dinitrogen monoxide
N2O
What is the exception to molecular compound naming?
Hydrogen compounds are unique and are not named with the prefix system.
The common name of C6H12O6:
Glucose
The common name of C12H22O11:
Sucrose
The common name of CH3OH:
Methanol
The common name of C2H5OH:
Ethanol
The common name of NH3:
Ammonia
The common name of CH4:
Methane
The common name of C3H8:
Propane
The common name of H2O2:
Hydrogen peroxide
The common name of H2O:
Water
Name this compound: N2O4
Dinitrogen tetraoxide
Name this compound: Silicon tetrachloride:
SiCl4
Non-polar:
Equal sharing due to equal electronegativity.
Polar:
Unequal sharing when electronegativities are different.
Do molecular compounds form crystal lattices?
No, instead they exist by themselves in unique shapes called discrete molecules.
Discrete molecules have (high/low) melting/boiling points.
low
How are metallic bonds formed?
By having low electronegativity atoms collide leading to a sharing of electrons with no chemical reaction. They are caused by the random attraction of a positive nucleus to the free-flowing valence electrons nearby. This is called a sea of electrons.
If a molecule has 4 bonding pairs, what shape is it most likely to be?
A tetrahedron.
If a molecule has 3 bonding pairs and one lone pair, what shape is it most likely to be?
A trigonal pyramid.
If a molecule has 2 bonding pairs and 2 lone pairs, what shape is it most likely to be?
Bent or angular.
If a molecule has 3 bonding pairs, what shape is it most likely to be?
Trigonal planar.
If a molecule has 2 bonding pairs and one lone pair, what shape is it most likely to be?
Bent or angular.
If a molecule has 2 bonding pairs, what shape is it most likely to be?
Linear.
What is the difference between metals and non-metals?
Nonmetal properties are not metallic. Metals usually are good conductors of electricity and heat, and can also be easily moulded. Nonmetals are poor heat and electricity conductors, except mercury other metals are solid at room temperature.
What is the difference between ionic and covalent bonds?
In ionic bonding, atoms transfer electrons to each other. Ionic bonds require at least one electron donor and one electron acceptor. In contrast, atoms with the same electronegativity share electrons in covalent bonds, because neither atom preferentially attracts or repels the shared electrons.
How do atoms become ions?
Ions are formed by the addition of electrons to, or the removal of electrons from, neutral atoms or molecules or other ions
Why do bonds form?
Atoms are trying to reach the most stable (lowest-energy) state that they can.
What is the difference between ionic and molecular compounds?
Molecular compounds are pure substances formed when atoms are linked together by sharing of electrons while ionic compounds are formed due to the transfer of electrons.
Dipole:
A bond/molecule that has two poles.
If a molecule is asymmetric it is…
polar.
If a molecule is symmetric and is bonded to only one other type of atom it is…
nonpolar.
If a molecule is symmetric and is bonded to many other types of atoms it is…
polar
London Forces:
Caused by the motion of electrons and their resulting attraction to the nuclei of nearby molecules. Weak. The increased number of dispersion forces results in different physical properties like boiling point.
What molecules have London forces?
All of them.
What molecule will have the most London forces?
The larger the compound, the more protons and electrons are available for LFD’s.
Dipole-Dipole Forces:
Similar to ionic bonds but much weaker. Significantly stronger than dispersion forces. Occur when oppositely charged regions of dipolar molecules attract.
What compounds have dipole-dipole forces?
Polar molecules that are electrostatically attracted to one another.
What molecules have the strongest dipole-dipole forces?
The greater the difference in electronegativities the stronger the dipole.
Hydrogen bonding:
Attractive forces where hydrogen is covalently bonded to a very electronegative atom which is also bonded to an unshared electron pair of an electronegative atom in a nearby molecule. Very strong, has a large effect on physical properties.
What compounds have hydrogen bonding?
Compounds that usually have F-H, O-H and N-H bonds.
What is VSEPR theory?
Valence shell electron pair repulsion theory states that electrons want to be as far from each other as possible.
