Chemistry Chapter 6
Explain what kinds of atoms form covalent and ionic bonds.
Ionic: between a metal and nonmetal or metal and or nonmetal and polyatomic ion. Covalent: two nonmetals or nonmetal and metalloid.
What does the octet rule state?
Is a chemical rule of thumb that states that atoms of main-group elements tend to combine in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas
Define nonpolar covalent bond.
A covalent bond in which the bonding electrons in the molecular orbital are shared equally is a nonpolar covalent bond.
Define polar covalent bond.
A covalent bond in which the bonding electrons in the rage molecular orbital are shared unequally is a polar covalent bond.
A ionic bond forms between.....
A metal and a nonmetal or a metal and or nonmetal and polyatomic ion
Define molecular orbital.
A molecular orbital is the region of high probability that is occupied by an individual electron.
Define dipole
A molecule in which one end has a partial positive charge and the other end has a partial negative charge is called a dipole.
What does Pauli Exclusion Principle state?
An orbital can hold a maximum of 2 electrons
Tell me the repulsive and attractive forces that take place in a covalent bond.
Attractive forces: the positively are attracted to the negatively charged electron clouds. Repulsive forces: the positively charged nuclei repel one another, as do the negatively charged electrons clouds.
Define Electronegativity
Electronegativity is a measure of the attraction of an atom for the electrons in a chemical bond. The higher the electronegativity of an atom,mother greater its attraction for bonding elections.
Define valence electron
Electrons on the outer most shell
Which of the following bonds has the strongest bond? H-F or H-Cl and why?
H-F because this bond has a larger electronegativity difference than H-Cl
List the exceptions to the octet rule:
Hydrogen and helium only need 2 valence electrons to have a full octet Boron is generally stable with 6 valence electrons (less than an octet)
Explain why an atom might hold partial positive and negative sign?
In a polar covalent bond, the shared pair of electrons is not transferred completely
In general, the greater the ___________ difference, the greater the ___________ and the stronger the bond.
In general, the greater the ELECTRONEGATIVITY difference, the greater the POLARITY and the stronger the bond.
Explain the differences between an ionic and covalent bonds.
Ionic bond: Forms between a metal and a nonmetal. They are stronger than covalent bonds and there is a transfer of electrons taking place. Covalent bond: Forms between two nonmetals or a metalloid and a nonmetal. They are weaker than ionic bonds and share electrons.
Explain why ionic bonds are electrically neutral.
Ionic compounds are electrically neutral because the sum of the cation and anion charges adds up to zero
Define bond length
The bond length is the distance between two bonded atoms at their minimum potential energy
Why is the bond length of two atoms an average number?
The bond length of two atoms is an average number because nuclei vibrate back and forth so the average length is then taken of the two nuclei including the movement
A covalent bond forms between.....
Two nonmetals or nonmetal and metalloid
Define Lewis dot structure
Use dots arranged around the chemical symbol of an element to represent the valence electron configuration of that element
Give me an example of a nonpolar and polar covalent bond.
Nonpolar: H2 - electrons shared equally Polar: H—F - electrons shared unequally. Fluorine being more electronegative will pull the electrons closer to it giving fluorine the partial positive charge and hydrogen a partial postive.
What does Hund's Rule state?
Orbitals of equal energy are each occupied by one electron first before any orbital is occupied by another electron
Which element is more electronegativity Boron or Oxygen?
Oxygen
Define bond energy
The energy required to break a bond between two atoms is the bond energy.