Podcast
Questions and Answers
Which statement accurately describes the solubility of substances?
Which statement accurately describes the solubility of substances?
What characterizes metallic bonding?
What characterizes metallic bonding?
Which of the following is a correct example of a polar covalent molecule?
Which of the following is a correct example of a polar covalent molecule?
What molecule is an example of a non-polar covalent substance?
What molecule is an example of a non-polar covalent substance?
Signup and view all the answers
Which property is NOT associated with covalent bonds?
Which property is NOT associated with covalent bonds?
Signup and view all the answers
What characterizes a coordinate (dative) covalent bond?
What characterizes a coordinate (dative) covalent bond?
Signup and view all the answers
In the Lewis structure of carbon dioxide (CO2), how many total lone pairs are present?
In the Lewis structure of carbon dioxide (CO2), how many total lone pairs are present?
Signup and view all the answers
Which statement accurately describes polarity in molecules?
Which statement accurately describes polarity in molecules?
Signup and view all the answers
In a Lewis structure, which of the following correctly depicts bonded pairs between atoms?
In a Lewis structure, which of the following correctly depicts bonded pairs between atoms?
Signup and view all the answers
Which of the following substances exhibits a coordinate covalent bond?
Which of the following substances exhibits a coordinate covalent bond?
Signup and view all the answers
What is the correct prefix for a molecule containing three atoms of an element?
What is the correct prefix for a molecule containing three atoms of an element?
Signup and view all the answers
Which of the following molecules is named using a special name rather than the systematic naming system?
Which of the following molecules is named using a special name rather than the systematic naming system?
Signup and view all the answers
Which suffix indicates that a molecule contains only two types of atoms?
Which suffix indicates that a molecule contains only two types of atoms?
Signup and view all the answers
What is a lone pair?
What is a lone pair?
Signup and view all the answers
What is the correct name for the molecule H2O?
What is the correct name for the molecule H2O?
Signup and view all the answers
What is the prefix for a molecule that contains four atoms of an element?
What is the prefix for a molecule that contains four atoms of an element?
Signup and view all the answers
Which of the following represents a coordinate covalent bond?
Which of the following represents a coordinate covalent bond?
Signup and view all the answers
Which of the following molecules is likely to be polar?
Which of the following molecules is likely to be polar?
Signup and view all the answers
Study Notes
Chemical Bonding
- Chemical reactions cause elements to bond to gain stability.
- Elements bond chemically to form a full octet of electrons (octet rule).
- The first four elements have an octet of 2 electrons.
- All other elements gain stability by gaining 8 valence electrons.
- Electronic configuration rules:
- First shell holds 2 electrons.
- Second shell holds 8 electrons.
- Third shell holds 8 electrons.
- Fourth shell up to 32 electrons.
- Elements bond to gain stability.
- Elements in groups 1-7 will bond to gain stability.
- Elements in group 8 are stable and don't bond (inert/unreactive). They already have a full octet of valence electrons.
- Elements bond to gain stability (full octet of valence electrons).
- Valence electrons participate in chemical bonding.
- Valence electrons are electrons in the outermost shell of an atom.
- Protons and neutrons are in the nucleus, they do not participate in chemical bonding.
- Types of chemical bonds:
- Ionic
- Covalent
- Metallic
Ionic Bonding
- Ionic bonds form between metal and nonmetal atoms.
- Metal atoms donate valence electrons to nonmetal atoms.
- Metal atoms become positively charged ions (cations).
- Nonmetal atoms accept valence electrons and become negatively charged ions (anions).
- Ionic bonds involve the electrostatic attraction between oppositely charged ions.
- Elements in groups 1 (alkali metals) and 2 (alkaline earth metals) are commonly used in ionic bonding.
- Hydrogen, though in group 1, is a nonmetal.
- Boron, though in group 3, is a metalloid, not a metal.
- Transition metals (elements 21-30) are not used in ionic bonding.
- The substance formed is called a compound.
- Compounds have a fixed ratio of elements.
- Compounds have a special name called a formula unit.
Steps in Ionic Bonding
- Write electronic configurations of the atoms.
- Determine if the atoms are a metal or a nonmetal.
- Draw the structures. Use dots for metal electrons and crosses for nonmetal electrons.
- Transfer valence electrons between atoms. Use arrows. Ensure both atoms become stable (metal has lost all outer electrons and nonmetal has gain 8 outer electrons).
- Redraw the structures. Place the charges in the top right corner of the atoms.
- Write the formula and the name.
How to write chemical formulas and formula names for ionic substances
- Write the symbol of the nonmetal first, and write the number to the right of the nonmetal representing the number of atoms.
- Write the symbol of the metal second, and write the number representing the number of atoms.
- To name the ionic substance: Write the name of the metal first, and write the name of the nonmetal second, but changing the ending of the nonmetal to "ide." Example: Chlorine becomes chloride.
Covalent Bonding
- Covalent bonding occurs between nonmetal atoms.
- Atoms share valence electrons.
- Molecules are formed.
- The molecules formed are called covalent molecules.
- Types of covalent bonds:
- Single bond (sharing 1 pair of electrons)
- Double bond (sharing 2 pairs of electrons)
- Triple bond (sharing 3 pairs of electrons)
Steps in Covalent Bonding
- Write the electronic configuration of your atoms.
- Determine if your atoms are a metal or a nonmetal. Both atoms must be nonmetals.
- Draw structures. Use dots for one atom and crosses to represent electrons.
- Place largest atom in the center. Place surrounding atoms around the central atom, sharing pairs of electrons with the central atom.
- Share valence electrons between atoms to form bonds. Make sure the atoms are stable (8 electrons in their valence shell). If not, try using double or triple bonds.
- Redraw the new structures (show the new electronic configurations) in brackets, and indicate the charge in the top right of atoms.
- Write the chemical formula and give the name.
How to write the chemical formulas and formula names for covalent substances
- Assess the structure to find how each element exists.
- Write the formula by writing the symbol of the central atom/atoms first, and noncentral atoms. Use subscripts to indicate the number of atoms for each element.
- Write the name by applying learned prefixes.
- Change the suffix for the second element to “ide.”
Covalent Bond Prefixes
Number of AtomsPrefix1Mono2Di3Tri4Tetra or Tetr5Pent6Hex7Hept8Oct
Other covalent compounds
- Some covalent compounds have special names based on historical usage.
- Example: Water (H₂O), Ammonia (NH₃).
Lone Pairs
- Lone pairs are valence electrons not involved in bonding.
- Lone pairs do affect the geometry.
- Lone pairs are important to chemical reactions, even if they are not bonded.
Lewis Structures
- Lewis structures illustrate atoms and their bonds in a molecule.
- Show pairs of electrons, whether bonding or lone.
Metallic Bonding
- Metallic bonds form between metal atoms.
- Valence electrons are delocalized (free to move).
- Metal ions are positively charged.
- Electrons share between metal ions.
- Asea of mobile electrons surrounds positive metal ions.
Metallic Properties
- Positive metal cations in a sea of mobile electrons.
- Electrons shared amongst all metal ions.
- Leads to a metallic lattice.
Polarity
- Some molecules are polar, which means they have positive and negative charges.
- Polar molecules arise when one atom exerts a stronger attractive force on the electrons in a bond.
- The electrons are pulled toward the atom with the stronger attractive force.
- Polarity is caused by differences in electronegativity.
- Like dissolves like.
Electronegativity
- Electronegativity is a measure of an atom's ability to attract electrons.
- The difference in electronegativity between two atoms indicates the type of bond.
- A small difference indicates a nonpolar covalent bond. A large difference indicates a polar covalent or ionic bond. (Refer to table for electronegativity ranges).
Summary of Chemical Bonds and Types
Type of BondAtoms InvolvedElectrons UsedHow Electrons are SharedExampleIonic BondMetal and non-metalElectrons transferredFull 'transfer' of electrons resulting in opposite charges; electrostatic attractionNaCl (sodium chloride)Covalent BondNon-metalsElectrons sharedSharing electrons to form pairs; attraction between shared electrons and both atomic nuclei.H₂O (water)Metallic BondMetalsElectrons delocalized/ free-floatingSea of mobile electrons that surround positive metal cations.Na (sodium)
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your understanding of solubility, bonding types, and molecular structure in this Chemistry Chapter 7 quiz. Questions cover topics such as polar and non-polar covalent bonds, metallic bonding, and the Lewis structure of molecules. This quiz is perfect for students looking to reinforce their knowledge in chemistry.
