Units 22-23 Flashcards
Ionic compound
A compound formed between a metal and a non-metal.
Crystalline solids at room temperature. Conduct electricity when molten or dissolved in water.
What is another name for ionic compounds?
Salts
Ionic bonding
The bonding in ionic compounds.
Why do ionic bonds have such high melting points?
Metal atoms lose electrons and become positive ions. Non-metal atoms gain electrons and become negative ions. Positives surround negatives and vice versa.
So each ion is experiencing attractive interactions with many ions of the other type.
True or False: All salts are brittle and cannot be easily reshaped.
True
True or False: Salts are ionic conductors
True
What is an ionic conductor?
Solids don’t conduct electricity, but salts dissolved in liquids DO.
True or False: Non-metal atoms want to keep their electrons so much they sometimes steal electrons from other atoms.
True
True or False: The bonding between ionic compounds and metal compounds is similar
False
Do metals or non-metals more easily gain electrons?
metals
Do metals or non-metals more easily LOSE electrons?
non-metals
True or False: In ionic bonding, metals and non-metals combine in a way that one atom completely gives and one atom completely receives, forming IONS (positive and negative).
True
True or False: Ionic bonds allow electrons to flow between multiple atoms freely.
False
Why are ionic bonds so strong if the electrons are bound to orbitals surrounding a specific atom?
Because of the electrostatic force/attraction between the many created positive and negative ions resulting from the bond.
Each atom is attracted to forces many atoms away from it, at great distances, as well as all those that are close. So they are all linked together like a spiderweb.
Kind of like World of Goo bonds between many atoms
How are ionic bonds shielded from the repulsive forces of their own positive/negative attractions?
Because each positive ion is surrounded by negative ions, and vice versa. This shields them from the repulsive forces and allows them to create many bonds.
True or False: Ionic bonds will always form in a way that leaves the compound electrically neutral
True
True or False: In ionic bonds, the negative and positive charges are equal, even though sometimes it takes more atoms of one type to achieve this.
True
True or False: Electrostatic forces are long range
True
Why do ionic bonds have high melting temperatures?
Because it takes a great deal of thermal energy to pull individual ions away from their many connected neighbors
Why do ionic compounds break so easily? Why are they brittle?
Because in order to flatten, bend, or change the shape of a compound, layers of atoms must slide over each other (in all matter).
But in ionic compounds, having a layer of atoms move over a bit, puts positive ions in direct contact with other positives, and negatives in contact with negatives. This creates strong repulsive forces that push the layers apart.
Electrolyte
A chemical compound that ionizes when dissolved in water to produce an electrically conductive medium.
True or False: Gatorade is a good electrical conductor
True
Why don’t solid salts conduct electricity?
Because electricity is conducted through flowing/moving electrons. But in ionic bonds, electrons are stuck in place. They can’t move, so electricity doesn’t flow.
Why can liquid salts conduct electricity?
When the solid melts, the electrons become free to move.
Why are salts usually transparent?
Because electrons are bound to specific discrete energy levels, they are not free to roam around. And it takes a higher energy than a photon of visible light to excite an electron to a higher energy level. UV or above.
The light energy does not excite the electrons, so they do not move to higher levels and become absorbed (emitting energy). They just pass through
What light range provides enough energy to cause salts to be opaque or colorful?
UV or higher
Why do salts appear white or cloudy?
Because of all the many cracks that are reflecting light (not absorbing visible light).
True or False: The metal and nonmetal atoms in ionic compounds form ions with the noble gas configuration
True
Octet rule
An atom will most likely form an ion that has the ns^2np^6 configuration of the closest noble gas atom.
What properties of salts change as a result of the ionic charge on transition metal ions?
Color and magnetism
Do ionic liquids conduct electricity as well as metals?
Nope
Do metals or nonmetals have large atoms?
Metals
Do metals or nonmetals have many valence electrons?
Nonmetals
Do metals or nonmetals have few valence electrons?
Metals
Out of metals and nonmetals, which one has high ionization energy? Which one low?
Metals = low
Nonmetals = high
True or False: A salt is a molecule
FALSE
It is network matter
Why don’t salts conduct electricity as well as metals?
Because the mass of the ions (positives and negatives) is greater than the mass of the electrons.
When will a salt be colored?
If it contains transition metal ions where low lying orbital levels (associated with the electrons in d orbitals) are found.
Which type of atom is placed first when naming a compound?
The metal
When forming the name of a compound, what does the nonmetal part END with?
-ide
What type of bonds create molecules?
Covalent
What type of bonds create the most diverse attributes of matter?
Covalent
What type of atoms make covalent bonds?
non-metal
True or False: Either filling every orbital in the valence shell or emptying it completely is an especially favorable arrangement.
True
How do metals fill their valence shell?
By releasing electrons.
How do non-metals fill their valence shell?
They acquire or share other electrons
Why don’t non-metals give off their electrons when pairing?
Because the energy cost is too high.
What is a single bond?
A covalent bond involving ONE PAIR of electrons shared between the two bound atoms.
Represented by single lines.
True or False: It doesn’t take very much energy to break a single bond.
False
Double bond
A covalent bond involving TWO PAIRS of electrons shared between the two bound atoms.
Represented by double lines
Triple bond
Atoms within a molecule connected by 3 bonds
True or False: Triple and double bonds are the strongest bonds known.
True
True or False: In covalent bonds, electrons are always shared equally.
False
Electronegativity
The measure of how strongly atoms attract electrons.
The ability to attract electrons.
What do you call an atom that can attract electrons well?
Electronegative
Polar
Bonds or molecules having an unequal distribution of charge. One end being positive, the other negative.
Dipole
Separation of positive and negative charge in a polar bond or molecule
Nonpolar
Bonds between two identical atoms. Nothing is special or superior about one or the other, because they’re the same.
True or False: covalent materials are generally easy to melt or boil
True
Intermolecular
Between molecules
As opposed to INTRAmolecular (within molecules)
True or False: A lot of covalent molecules have negatively and positively charged ends that help them attract other molecules
True
Why do covalent atoms attract?
Polar molecules
Hydrogen bonding
Interactions between hydrogen atoms bound to oxygen, nitrogen, or fluorine with OTHER oxygen, nitrogen, or fluorine atoms.
True or False: Hydrogen bonds are ultra strong, among the strongest known.
True
What is responsible for the high melting and boiling points of water?
Hydrogen bonds
True or False: We know that electrons move around an orbital and we know HOW they move.
False
THEY DO MOVE, but we don’t know how
Why does the electron charge density constantly change in an atom overall?
Because electrons are moving around their orbitals.
Dispersion forces
Weak intermolecular attraction arising from the formation of temporary dipoles in non-polar molecules.
Electrons moving in orbitals causes positive and negative areas of the atom to shift. It is this shifting that causes dispersion forces.
What’s another name for dispersion forces?
Van der Waals forces
True or False: Dispersion forces are strong
False
What are the weakest types of dispersion forces?
Forces between atoms or non-polar atoms (that rely on shifting electrons).
True or False: Covalent bonds always create molecules
False
Self-ionization
The reaction of certain neutral molecules (like water) with other identical molecules to produce cations and anions
pH
A measure of the concentration of hydronium (H3O+) ions in water.
pH = 7 is neutral
Acidic
Having a pH value less than 7, meaning that the hydronium ion concentration is GREATER (not a typo) than in pure water.
Basic
Having a pH value greater than 7, meaning that the hydronium ion concentration is LESS than in pure water (not a typo).
Molecular ion
Groups of atoms covalently bound to each other that have a net charge because electrons have been lost or gained in the formation process.
What’s another name for molecular ions?
Polyatomic ions
True or False: Covalent materials can conduct electricity
FALSE
Not at all. The electrons are completely stuck.
Dipole - dipole interactions
Weak intermolecular attractions between polar molecules.
Valence shell
The outermost, highest-energy set of orbitals in an atom.
True or False: The dipole is stronger when it’s separated more.
True
True or False: Like dissolves like
True
buckminsterfullerenes
Tiny carbon soccer ball
Called Bucky balls for short
