Chem Test
What is bonding? - an attractive force that holds atoms together
Why does it happen? - To achieve less reactivity, decrease the components' energy, and complete the octet
what’s involved? - Valence Electrons
3 steps of ionic bonding -
loss/gain of electrons
formation of positive/negative ions
attraction of the ions due to opposite forces
Forming of covalent bonds - atoms share electrons
what is an intermolecular force? - force that affects how close together a substance’s molecules are
strongest intermolecular force - Hydrogen Bonds
which intermolecular force is always present? - Dispersion
electronegativities across a period - Electronegativity increases because as you go across the number of protons becomes bigger causing the nucleus to expand. When it expands the nucleus is bigger than the atomic radius so the pull on the bond is stronger.
electronegativities down a group - Electronegativity decreases because as you go down, the quantum level increases which causes the valence electron to be farther away from the nucleus, weakening the pull.
How does electronegativity affect bonding? - it determines how electrons are shared or transferred between atoms and it decides if the bond is polar, nonpolar, or ionic.
what happens when a covalent bond is formed? -
electrons are not gained or lost
they are shared somewhere between the 2 atoms
doesn’t belong to either atom
molecule - Covalent compound
formula unit - Ionic compound
Covalent bond - 2 or more non-metals
Ionic bond - one metal and one non-metal (polyatomic ions)
Covalent compound characteristics -
non-metals
shared electrons
atoms remain neutral
shared electrons hold bond
Ionic Compound characteristics -
Metal + non-metal
electrons lost/gained
atoms become ions
attraction of opposite charges
VSEPR - Valence Shell Electron Pair Repulsion Theory
3 - 120 - trigonal planar
4 - 109.5 - tetrahedral
(4) - 108 - linear triatomic
5 - 107 - pyramidal
6 - 105 - bent triatomic
7 - 180 - linear