Covalent Bonds Flashcards
Why do atoms lose or gain electrons?
in order to reach stability and have a saturated outershell (octet)
What is a covalent bond?
covalent bond occurs when 2 non metals share valence electrons
Descrive the three different types of covalent bonds
single: 2 electrons are shared
double: 4 electrons are shared
triple: 6 electrons are shared
What are sigma bonds?
single bonds
What are pi bonds?
double bonds
How are triple bonds arranged in pi and sigma
two pi bonds and one sigma for triple bonds
What factors determines strength of covalent bonds?
bond dissociation energy and bond length
How does bond length affect strength of the bonds?
the shorter the bond length, the stronger the bond
What is bond dissociation energy?
amount of energy needed to break a covalent bond
How does bond dissociation energy affect bond strength?
smaller bond length, greater bond dissociation energy
high bond dissociation energy, stronger the bond
Which is the strongest bond and which is the weakest?
triple bond is the strongest because it’s the shortest and has high bond dissociation energy
single bond is the weakest because it’s the longest and has low bond dissociation energy
What is endothermic reaction?
when more energy is required the break the bonds of the reactants than the amount of energy released when the bonds are forming
What is exothermic reaction?
when more energy is released when the bonds are forming than when the bonds are breaking
