Unit 1 The periodic table Flashcards
Define relative/natural abundance
Is a consistent ratio found in nature for given elements.
What is atomic mass of an element?
Is the weighted average of the mass of its isotopes.
Define weighted average
means some values have greater impact of the average than others.
What are some important points when calculating relative abundance?
- the larger isotope number is “x”
- the first step to isolating “x” is to multiply both sides by 100
What are the two rules that need to be followed for adding electrons to the orbital box diagrams?
1) Pauli Exlusion Principle
2) Hund’s Rule
Describe the two rules for the orbital box diagram
Pauli Exclusion Principle:
- The maximum number of electrons in each orbital is two. If two electrons are in one orbital, they must have opposite spins.
Hund’s rule:
- When adding electrons to a sublevel with more than one orbital, the electron spins must be all the same until each orbital has one electron.
What is the Aufbau principle?
Electrons fill sublevels starting with the lowest energy level up to highest energy.
State the limitations of the Bohr Model
Assumes or suggests:
- electrons orbit the nucleus/is predictable
- shape of orbits/shells are all spherical
- an incorrect scale of an atom
- energy of electrons in a level are all the same
What are the exceptions to the full electron configuration?
- Nearly full “d” sublevels will take an electron from the closest “s” sublevel to be full
- Nearly half full “d” sublevels will take an electron from the closest “s” sublevel to be half full
What is the electromagnetic spectrum order in increasing energy?
Radiowaves, Microwaves, infrared, visible, untraviolet, x-rays, gamma rays
How are the elements of the periodic table arranged?
By increasing atomic number
What is the significance of the periodic groups?
The elements in the groups have similar chemical properties.
- same number of valence electrons
What is the name of group 1?
Alkali metals
What is the name of group 2?
Alkaline earth metals
What is the name of groups between group 2 and 3?
Transition metals