1.5- MORE ABOUT ELECTRON ARRANGEMENTS IN ATOMS Flashcards
What is different about electrons from different shells?
differing amounts of energy
What are the shells called?
main energy levels
How are the main energy levels labelled?
1, 2, 3 and so on
What is the formula for the maximum number of electrons in each main energy level?
2n²
n is number of main level
What are the main energy levels divided into?
sub-levels
What are the sub-levels called?
s, p, d and f
What is different about the sub-levels?
they have slightly different energies
Level 1 sub-level
s
Level 2 sub-level
s
p
Level 3 sub-level
s
p
d
What is used for a more complete description of the electrons in atoms?
theory called quantum mechanics
When was quantum mechanics developed?
during the 1920s
What does the quantum mechanics theory describe?
describes the atom mathematically with an equation
What does the solution to the equation from quantum mechanics give?
probability of finding an electron in a given volume of space called an atomic orbital
What is the electron considered as?
a cloud of negative charge
What does an electron fill?
a volume in space called its atomic orbital
What is different about each main level of the atomic orbitals?
they have different shapes
What is different due to the difference in shape?
in turn they have slightly different energies
What do the shapes of the orbitals represent?
volume of space in which there is a 95% chance of finding an electron and influence shape of molecules
Something about the energy of 4s and 3d
4s is slightly lower in energy than 3d for neutral atoms
What property can electrons have?
spin
What must two electrons in the same orbital have?
opposite spins
How is writing the electronic structure simplified?
use the previous noble gas symbol
Elements that don’t follow the 4s before 3d rule?
chromium and copper
