Next time, click the stars (or press S) to bookmark difficult terms for review.
what are molecules?
molecules are the smallest part of a covalent compound, just as formula units are the smallest part of an ionic compound or atom are the smallest part of an element.
what are covalent bond?
a single pair of electrons is shared in an area centered between two atoms
which bonds are formed by group 7A elements?
Group 7A elements all form single bonds because they all have seven valence electrons
what are Double Covalent Bond?
when two pairs of electrons are shared. (e.g O2)
How many covalent bond do O2 form?
O2 forms two covalent bonds because oxygen has two valence electrons
what are Triple Covalent Bond
when three pairs of electrons are shared. (e.g N2)
what are the bonds formed by N2?
N2 forms three covalent bonds because oxygen is in Group 5A and needs to share three valence electrons
what is a Pi-bond?
when parallel orbitals overlap, it is the name given to a second or third covalent bond
what is the strongest bonds?
Triple bonds are stronger and shorter than double bonds, and they are stronger and shorter than single covalent bonds
what is Exothermic Reactions?
when more energy is released forming new bonds than in breaking old bonds
what is Endothermic Reactions?
when more energy is required to break old bonds than to form new bonds
covalent bonding bonds _________ to ________.
Nonmetals to Nonmetals
The distance between the atoms is called?
A covalent chemical bond is one in which
outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms
What is the maximum number of covalent bonds an element with atomic number 8 can make with hydrogen?
A molecule of carbon dioxide (CO2) is formed when one atom of carbon (atomic number 6) is covalently bonded with two atoms of oxygen (atomic number 8). What is the total number of electrons that must be shared between the carbon atom and the oxygen atoms in order to complete the outer electron shell of all three atoms?
What results from an unequal sharing of electrons between atoms?
a polar covalent bond
A covalent bond is likely to be polar when
one of the atoms sharing electrons is much more electronegative than the other atom.
What is an example of a molecule that contains a strong polar covalent bond?
Sometimes atoms form molecules by sharing two pairs of valence electrons. When this occurs, the atoms are said to be joined by