Ken Tao is the MedSchoolCoach expert on MCAT, and uses the acronym “BEAR” to help you remember the periodic trends for basicity, electronegativity, electron affinity, and ionization energy, acidity and radius.
All right. Welcome back to another MCAT Mnemonic Monday. I’m Ken and I’m an MCAT expert with MedSchoolCoach. Today we have another general chemistry mnemonic for you and that mnemonic is for periodic trends.
The periodic trends tell you in which direction of the periodic table do you have increasing values for different chemical properties. The mnemonic is bear: B E A R.
And each letter stands for different chemical properties. B stands for basicity, the ability of molecules to accept protons. As you can see, basicity increases going up and to the left of the periodic table.
E stands for three things: Electronegativity, Electron affinity, and ionization Energy. All of these E’s increase going up and to the right of the periodic table.
Electronegativity is the ability of an atom to attract electrons to itself at a covalent bond.
Electron affinity is the energy associated when you add an electron to an atom.
Ionization energy is the amount of energy required to remove an electron from an atom.
Next we have A, which stands for Acidity. This is the ability of a molecule to donate protons and solution. Acidity increases going down and to the right on the periodic table.
And finally we have R which is Radius. Radius is the size of an atom’s electron cloud and it increases going down and to the left on the periodic table.
So again the mnemonic is Bear: B E A R.