Chapter 4- Structure Flashcards
What is meant by the term ‘isotope’?
Isotopes are atoms of an element that have the same number of protons and electrons but different numbers of neutrons
Which sub-atomic particles are present in the nuclei of atoms?
Positively charged protons and neutral neutrons. Both have a relative mass of 1
In a neutral atom, what’s the ratio of electrons to protons?
1:1. This is because electrons have a relative charge of -1 and protons are +1
Why is the chemistry of an atom not affected by being an isotope?
They don’t have a charge, so don’t affect how protons and electrons interact
What does change between isotopes?
Physical properties, like mass, and melting and boiling points
How does alpha decay convert one atom to another?
A helium nucleus is released, reducing the mass number by 4 and atomic number by 2. The new atom has a charge of 2-.
How does beta decay convert one atom to another?
A neutron turns into a proton, and an electron leaves the atom. The mass number stays the same but the atomic number increases by 1. The charge is 1+
Energy=
frequency x Planck’s constant (6.626*10^-34)
Speed of light (2.998*10^8)=
frequency x wavelength
How is E=hv combined with c=vλ?
v=c/λ
∴ E=hc/λ
How is the energy of a photon converted into energy per mole?
Times by Avogadro’s constant (6.022*10^23)
What are the four quantum numbers that can be assigned to electrons?
Principal QN, azimuthal QN, magnetic QN, spin QN
What does the principle quantum number (n) represent?
The energy level
What values can the principle quantum number take?
1, 2, 3, …, ∞
What does the azimuthal quantum number (ℓ) represent?
The angular momentum of an atomic orbital (orbital type)
What values can the azimuthal quantum number take?
0, 1, 2, …, (n-1)
What does the magnetic quantum number (ml) represent?
The orientation of orbital in space (the specific orbital)
What values can the magnetic quantum number take?
-ℓ to +ℓ, inclusive of zero
What does the spin quantum number (ms) represent?
Which way the electron is spinning
What values can the spin quantum number take?
±0.5
State the aufbau principle
The aufbau principle states that in the ground state of an atom/ion, electrons fill atomic orbitals of the lowest available energy levels before filling higher levels
What is the Pauli exclusion principle?
Electrons in the same atom can’t have the exact same four quantum numbers
State Hund’s first rule
Every orbital in a sublevel is singly occupied before any orbital is doubly occupied. All of the electrons in singly occupied orbitals have the same spin (to maximize total spin).
What do boundary surface diagrams represent?
Boundary surface diagrams are a good representation of shapes of atomic orbitals. Boundary surface diagrams are considered an acceptable approximation of shape of orbital if the boundary surface encloses the region with probability density of more than 90%.
