Alevel Chemistry - Topic 1 Flashcards
Define Atomic Number
Atomic number: The number of protons in the nucleus of an atom of that element
Define mass number
Mass number: The sum of the number of protons and number of neutrons in the nucleus of that atom
Isotopes
Isotopes: Atoms of the same element with the same number of protons but differ in the number of neutrons
Define Relative atomic mass
Relative atomic mass: The weighted mean mass of an atom of an element compared to 1/12th the mass of an atom of Carbon-12
Define Relative isotopic mass
Relative isotopic mass: The mass of an atom of an isotope compared to 1/12th the mass of an atom of Carbon-12
What is effective nuclear charge?
effective nuclear charge is the actual amount of positive charge experienced by an electron in a multi-electron atom
What is the relative mass and charge of a neutron, proton, and electron?
Neutron: 1, 0 charge
Proton: 1, +1 charge
Electron: 1/1840, -1 Charge
What are isoelectronic species?
Isoelectronic species are elements or ions that have the same, or equal number of electrons. E.g. Na+, F- both have 10 electrons.
What are the two exceptions in electronic configurations?
Copper and chromium, will fill their 4s sub shell with an electron so that the 3d Sub shell is either half or completely full since this is the most stable state.
What is the maximum number of electrons that can occupy each shell?
Number of electrons = 2n^2
E.g. 2,8,18,32
What is Hunds law?
Electrons will occupy orbitals singly before pairing takes place
What is paulis exclusion principle?
Electrons cannot occupy the same orbital unless they have opposite spins
What is an orbital?
Region within the atom than can hold up to two electrons with opposite spins
What is the shape of a S-Orbital
Sphere
What is the shape of a P-Orbital
Dumbbell