Chem mid term test Flashcards
What is electron configuration?
The arrangement of electrons in an atom’s orbitals.
What is the Aufbau Principle?
Electrons fill orbitals starting from the lowest energy level to the highest.
What is the Pauli Exclusion Principle?
No two electrons can have the same set of quantum numbers.
What is Hund’s Rule?
Electrons will occupy degenerate orbitals singly before pairing up.
What are quantum numbers?
Numbers that describe the properties of atomic orbitals and the electrons in those orbitals.
What is an orbital filling diagram?
A visual representation of the electron configuration of an atom.
What is the trend for atomic radius?
Atomic radius increases down a group and decreases across a period.
What is first ionization energy?
The energy required to remove the outermost electron from a neutral atom.
What is the trend for first ionization energy?
First ionization energy increases across a period and decreases down a group.
What is electronegativity?
The tendency of an atom to attract electrons in a bond.
What is the trend for electronegativity?
Electronegativity increases across a period and decreases down a group.
What is Avogadro’s number?
6.022 x 10²³, the number of particles in one mole of a substance.
How do you convert between particles and moles?
Use Avogadro’s number as a conversion factor.
How do you calculate molar mass?
Sum the atomic masses of all atoms in a molecule.
What is percent composition by mass?
The percentage by mass of each element in a compound.
What is an empirical formula?
The simplest whole-number ratio of elements in a compound.
What is the difference between empirical and molecular formulas?
Empirical formulas show the simplest ratio, while molecular formulas show the actual number of atoms.
What is stoichiometry?
The calculation of reactants and products in chemical reactions.
What is a limiting reactant?
The reactant that is completely consumed in a reaction, limiting the amount of product formed.
What is theoretical yield?
The maximum amount of product that can be formed from given reactants.
What is actual yield?
The amount of product actually produced in a reaction.
What is percent yield?
The ratio of actual yield to theoretical yield, expressed as a percentage.
How do you calculate percent yield?
Percent yield = (actual yield / theoretical yield) x 100.
