True or false: The closer to the nucleus electrons are, the stronger their attraction the nucleus.
True
Using the names, state the chemical formulas for each molecular compound
Using the formulas, name the molecular compounds:
What are molecular compounds?
Molecular compounds are compounds that are composed of two or more non metallic atoms of different elements joined by covalent bonds.
What are diamotic and polyatomic elements? List each of them
Diamotic elements are composed of two atoms of the same element joined by a covalent bond. The diamotic elements are hydrogen (H2 gas), nitrogen (N2 gas), oxygen (O2 gas), fluorine (F2 gas), chlorine (Cl2 gas), bromine (Br2 liquid), and iodine (I2 solid). Meanwhile, polyatomic elements are composed of many atoms of the same element joined by covalent bonds. The polyatomic elements include phosphorus (P4 solid), sulfur (S8 solid), and Ozone (O3).
What are molecular elements?
Molecular elements do not exist naturally as single atoms; they consist of two or more nonmetallic atoms of the same elemtn joined by a covalent bond.
What is a molecule?
A molecule is an independent unit made up of fixed numbers of nonmetallic atoms held together by covalent bonds. Ex. CH4 (g)
List the properties of ionic compounds given to them because of ionic bonding and their crystalline structure.
1. Ionic compounds are hard- non directional ionic bonds are strong and diffcult to break
2. Ionic compounds are brittle- Ions cannot be reaaranged without breaking the crystal lattice structure, thus it is a very brittle strcuture to allow for easy rearrangement.
3. Ionic compounds have high melting and boiling points- This is because ionic bonds require large amounts of energy to break and ions are bonded in all directions, making the bonds even harder to break.
4. Most ionic compounds are soluble due to the attraction between ions and the partially positive and negative ends of polar water molecules.
5. Ionic compounds in a liquid/solution are electrolytic (can conduct electricity) due to the presence of moving ions.
6. Ionic compounds are relativley stable and unreactive at SATP (standard ambient temperature and pressure) because their valence shells are full.
Why is ionic bonding non-directional?
because an ion has the same attraction from all directions for an ion of opposite charge.
How do ions arrange themselves?
Ions arrange themselves in a crystal lattice structure where the maximum total attraction between cations and anions occurs.
for atoms in an electron dot diagram, do you use square brackets around it?
no.
For anions do you draw any electrons around the symbol in an electron dot diagram? If so/not, why?
You do, this is because anions take in electrons to fill up their valence shells. So, you draw a full valence shell around the anion.
For cations do you draw any electrons around the symbol in an electron dot diagram? If so/not, why?
You do not, This is because they give all of their electrons in the valence shell away.
When do you use square brackets around the element symbol in an electron dot diagram?
When you are representing an ion.
Describe what all of the symbols in an electron dot diagram mean.
The element symbol is written to represent the nucleus and any filled energy levels below the valence shell. Each of the four sides around the element symbol represent an oribtal. Electrons are represented with dots that surround the element symbol
What are electron dot diagrams?
Electron dot diagrams, also called lewis symbols, are a structural representation of the location of valence electrons in an atom or ion.
What is an ionic bond? Under what conditions are ionic compounds allowed to form?
An ionic bond is the simultaeneous attraction of oppositley charged ions. Ionic bonds form when there is an electronegativity difference between atoms that is greater than 1.7. This results in the complete transfer of one more electrons from the atom with lower electronegativity to the atom with higher electronegativity. Since metals have lower electronegativity values and nonmetals have higher electronegativity values, ionic compounds are typically composed of a metal and a non-metal.
What does the octet rule (the duet rule for hydrogen) state?
The octet rule states that chemical reactions involve the sharing or transfer of valence electrons so that each atom has a complete valence shell/ a stable octet. Atoms are more stable when they have a complete valence shell of electrons (explains the stability of noble gases).
What usually tends to have high electronegativities and what usually tends to have low electronegativites (metals/nonmetals)
metals tend to have low electronegativites and nonmetals tend to have high electronegativites.
True or false. The greater the number of electrons in the nucleus, the smaller the attraction for electrons.
False. The greater the number of electrons in the nucleus, the greater the attraction for electrons.
Would electronegativity increase or decrease if you increased the atomic number but kept the number of energy levels the same (within a period)? Why?
electronegativity would increase in that scenario because there are now more protons within a similar distance to the electrons, meaning that the attraction between electrons and protons/ the nucleus will increase.
Would electronegativity increase or decrease with less energy levels? Why?
Electronegativity would increase with less energy levels because the less energy levels there are, the closer the electrons would be to the nucleus, making that attraction stronger.
What is electronegativity?
Electronegativity is the relative ability of an atom to attract bonding electrons.
How can you quickly determine the amount of energy levels an element has.
Based off of the period it's in (period 1 elements have one shell, period 2 elements have two and so on)
How can you quickly determine the number of valence electrons a main group element has?
look at the group number for the main group elements and subtract it by 10 if it has double digits, if it dosen't have double digits just take that number. (main group elements are elements in groups 1, 2, and 13-18)
How do electrons spread themselves out in orbitals?
Electrons spread out to occupy any empty orbitals before forming electron pairs.
How many orbitals does the first energy level contain? What about energy levels above the first energy level?
The first energy level has one orbital (hydrogen and helium have one orbital each). Energy levels above the first one have four orbitals each.
How many electrons does a half filled orbital contain? What is the description of the electrons in that orbital? and what types of electron can be found in a half filled orbital? What about a filled orbital?
half filled orbital: there is 1 one electron in a half filled orbital. This electrons is described as unpaired and this type of electron is bonding.
filled orbital: There are 2 electrons in a filled orbital, these electrons are described as lone pairs, and these types of electron is known as nonbonding
Define orbital:
An orbital is a specific volume of space in which an electron of certain energy is likely to be found. An orbital may be unoccupied, contain one electron, or contain two electrons.
state the steps required to write formulas of ionic compounds:
1. write the symbol for the cation followed by the symbol for the anion
2. determine the total number of each ion required to balance the charges so that the compound is electrically neutral
3. use subscripts to indicate the ratio of cations to anions (no subscript for single ion and use brackets around polyatomic ions when a subscript is needed in the formula)
4. indicate the state of matter with a lowercase letter in brackets after the chemical formula (all ionic compounds are solid at room temp and pressure)
state the steps required to name ionic compounds
1. Name the cation first by using the elements name (if the cation is a multivalent element, more than one possible charge, indicate the charge after the cation name using roman numerals. You will have to use the anion charge and work backwards to find the cation charge)
2. name the anion second by using the first part of the elements name and changing the end to "ide" (if the anion is a polyatomic ion do not change the ending to "ide")
True or false: the formulas for ionic compounds represent the simplest whole number ratio of ions that result in a net charge of 0
True
How do crystal lattices form?
Crystal lattices form when multiple units of a polar compound come together to form a repeating structure. The reason they become polar is due to their differences in electro negativity (the electrons shift to the side of the compound that is more electronegative making that side negative and the other side positive)
What is the stereochemical formula?
It is a structural diagram that represents the 3-D molecular shape based on VSEPR theory
(thick triangle means coming towards you, dotted line means going away from you, and straight normal line just means within the plane of the page)
What is the structural formula?
The structural formula shows which atoms are bonded and the type of covalent bond is represented by the number of lines drawn between the atomic symbols.
What is a lewis formula?
A lewis formula shows electron sharing and the formation of stable valence octets of electrons in molecules and ions. Always draw the lewis formula first.
What is a molecular formula?
A molecular formula shows the actual number of atoms that are covalently bonded to make up each molecule; usually arranged to show atom configuration.
What is an empirical formula?
An empirical formula shows the simplest whole number ratio of atoms in the compound.
What do you say when two non metals bind through an electrostatic attraction?
It is a molecular compound with ionic properties.
What is bonding capacity determined by?
the number of bonding electrons.
What is bonding capacity?
Bonding capacity is the maximum number of single covalent bonds that an atom can form. (you cannot have 4 or more covalent bonds with the same atoms)
(an atom with a bonding capacity of 3 can form 3 single covalent bonds, 1 single covalent bond and one double bond, or 1 triple covalent bond)
Diffrentiate between a single covalent bond, a double covalent bond, and a triple covalent bond.
A single covalent bond involves one pair of shared electrons.
A double covalent bond is a multiple bond consisting of two pairs of shared electrons.
A triple covalent bond is a multiple bond consisting of three pairs of shared electrons.
When can convalent bonds occur?
When the electronegativites of both atoms, usually non metals, are relativley high and the electronegativity difference beween atoms is 1.7 or less.
What is a covalent bond?
A covalent bond is the simultaneous attraction of two nuclei for a shared pair of bonding electrons, forming a strong, direction intramolecular force, giving each atom a complete valence shell.
What is the molecular shape in the VSEPR theory determined by?
the molecular shape is determined by the positions of the electron pairs when they are a maximum distance apart and whether they are bond pairs or lone pairs.
What does the VSEPR theory state?
The VSEPR theory states that pairs of electrons in the valence shell of an atom stay as far apart as possible because of the repulsion of their negative charges
What does VSEPR theory stand for?
Valence-shell-electron-pair-repulsion theory
What is stereochemistry?
Stereochemistry is the study of the 3-D spatial configuration of molecules
What stereochemical formula is this lewis diagram representing?
Linear (tetrahedral electron arrangement)
State the number of bonding regions on the central atom, the amount of lone pairs on the central atom, the VSEPR class, and the geometry of the stereochemical formula
number of bonding regions on central atom: 1
number of lone pairs on central atom: 3
VSEPR class: AXE3
Geometry: Linear (tetrahedral electron arrangement)
What stereochemical formula does this lewis structure represent.
Angular/bent/ V-shaped (tetrahedral electron arrangement)
What stereochemical formula does this lewis structure represent
Angular/bent/V-shaped (trigonal planar electron arrangement)
State the number of bonding regions on the central atom, the amount of lone pairs on the central atom, the VSEPR class, and the geometry of the stereochemical formula
Bonding regions on central atom: 2
Lone pairs on central atom: 1/2
VSEPR class: AX2E/ AX2E2
Geometry: Angular/bent/V-shaped (trigonal planar electron arrangement for 1 lone pair and tetrahedral electron arrangment for 2 lone pairs)
state the stereochemical formula this lewis structure is representing:
Trigonal pyrimidal (tetrahedral electron arrangment)
State the number of bonding regions on the central atom, the amount of lone pairs on the central atom, the VSEPR class, and the geometry of the stereochemical formula
Bonding regions (X) on central atom (A): 3
Amount of lone pairs (E): 1
VSEPR class: AX3E
Geometry: Trigonal pyramidal (tetrahedral electron arrangment)
What type of stereochemical formula is this?
Tetrahedral
State the number of bonding regions on the central atom, the amount of lone pairs on the central atom, the VSEPR class, and the geometry of the stereochemical formula
Number of bonding regions (X) on central atom (A): 4
The amount of lone pairs (E) on the central atom: 0
VSEPR class: AX4
Geometry: Tetrahedral
What type of stereochemical formula would this be?
Trigonal planar
State the number of bonding regions on the central atom, the amount of lone pairs on the central atom, the VSEPR class, and the geometry of the stereochemical formula
Bonding regions on central atom: 3
Lone pairs on the central atom: 0
VSEPR class: AX3
Geometry: Trigonal planar
What type of stereochemical formula is this lewis strcutre representing?
Linear.
State the number of bonding regions on the central atom, the amount of lone pairs on the central atom, the VSEPR class, and the geometry of the stereochemical formula
Bonding regions on central atom: 2
Lone pairs on central atom (E):0
VSEPR class: AX2 (A is central atom and X is satellite)
Geometry: Linear
when do ionic compounds form?
when valence electrons transfer from one atom to the other resulting in the formation of a cation (usually a metal) and an anion (usually a nonmetal). Once the formation of a cation and an anion has occured, they become attracted to one another by charge, forming a neutral ionic compound joined by an ionic bond. Ex. Sodium and chlorine joining together to form sodium chloride. (One sodium ion and chlorine ion joined by an ionic bond represents one formula unit of sodium chloride)
Using the names, state the chemical formulas for each molecular compound