Basic Organic Concepts - ALL NOTES Flashcards
Define atomic number ?
-number of protons in nucleus
Define mass number ?
-Number of protons and neutrons in an atom
What is a cation?
-A positively charged ion
What is an anion?
-A negatively charged ion
What is a mole?
-the Avogardro number of particles in a substance
What is Avogadro’s number?
-6.022x10^23
What happens to atomic size across period ?
-Decreases
What happens to atomic size across group?
-Increases
What happens to the number of valence electrons across period?
-Increases
What happens to the number of valence electrons across group?
-Remains the same
What happens to metallic character across period?
-Decreases
What happens to metallic character across group?
-Increases
What happens to electron affinity across period?
-Increases
What happens to electron affinity across group?
-Decreases
What happens to electronegativity across period ?
-Increases
What happens to electronegativity across group?
-Decreases
What happens to ionisation energy across group?
-Decreases
What happens to ionisation energy across period?
-Increases
What is molarity?
-The number of moles of solute per litre of solution
What are valence electrons?
-Electrons in the outermost shell
What is valence?
-The number of electrons an atom must lose or gain to attain the nearest noble gas
How many orbital does the S shell have?
-1
How many orbitals does the P shell have?
-3
How many oribitals does the D shell have?
-5
How many orbitals does the F shell have?
-7
What is the ground state of electron configuration ?
-The lowest energy in an atom
What is the excited state electron configuration?
-The highest energy in an atom
What is the Aufbau principle?
-Electrons occupy the orbitals of lowest energy first
What is the Pauli Exclusion Principle?
-Each atomic orbital can hold a maximum of 2 electrons with opposite spin
What is Hund’s rule?
-When there are two or more orbitals of the same energy, electrons go on different orbitals rather than pair up
What is electronegativity ?
-The power of an atom in a molecule to attract electrons to itself
What intermolecular forces determine physical properties In molecules ?
-Diipole-dipole Waals interactions
-Van Der Waals forces
-Hydrogen bonds
What are the Dipole-Dipole interactions?
-Interactions between the positive end of one dipole and the negative end on another
What are the Van Der Waals forces?
-Weak forces of attraction between non-polar molecules
What are hydrogen bond interactions?
-Attractive forces between hydrogen attached to electronegative atom of one molecule and an electronegative atom of the same or different molecule
How can carbon have 4 valence electrons but only 2 available ?
-A small amount of energy is used to unpair one of the 2s and move onto 2p to allow large energy output
What is sp3 hybridisation of carbon?
-Carbon forms 4 single binds eg. CH4
What is sp2 hybridisation of carbon?
-Carbon forms a double bond eg. C2H4
What is sp hybridisation of carbon?
-Carbon forms a triple bond or two double bonds to one carbon atom
How to fill orbitals ?
How to draw bond etc?
