Atomic structure Flashcards
atomic orbitals
regions around nucleus that can hold up to two electrons with opposite spins
fact about the two electrons in the same orbital
they have opposite spins (up or down)
due to repulsion forces
between the two negatively charged e-
what is an electron
a cloud of negative charge
what does an orbital show
predicts (95% accurate) the location of an electron
s orbital explained
spherical shaped
every electron shell has 1 s subshell
there is one orbital for s
the s orbital can hold a maximum of 2 electrons
s block starts at
p orbitals explained
dumbbell shaped
there are three p subshells
each orbital can hold 2 e- (total 6 electrons)
p-block starts at boron
d orbital explained
there are 5 d subshells
each orbital hold 2e-
holds 10 electrons in total
d block starts at scandium
f orbitals explained
there are 7 f subshells
two electrons in each orbital
so 14 electrons in total
what is a subshell
all of the same type of orbitals
rules for filling atomic orbitals
orbitals with lowest energy levels are filled first
each orbital can hold two opposite spin e-
when subshells are getting filled, an electron goes to each orbital before filling an orbital
why do electron get shared across same energy level orbitals before filling up an orbital
to reduce the repulsion forces experienced between two same (-) charged electrons in the same orbital
why is the 4s energy subshell filled before 3d
4s has a lower energy level than 3d
chromium and copper electron configuration difference
and why
the 4s orbital contains one electron
even though there are electrons in the 3d subshell
has only 4s electron so that the 3d subshell can be half full or completely full so it is more stable
where is the s block elements located
first two groups including helium
starting from hydrogen (1s^1)
where is the p block elements located
right side of the periodic table
starting from boron (2p^1)
where is the d block elements located
middle (transition metals)
starting from scandium (3d^1)
how to write the shorthand electron configuration
only the number of electrons in the outer shell is needed
put the name of the group 0 (noble gas) in square brackets, that comes before the element
then write out the remainder of the config
what happens to the 4s subshell when it has electrons in it
becomes a higher energy level than 3d
so when electrons are removed (ion formed) from a d block element where do they lose electrons from
because when a 4s subshell has an electron in it (even though it initially had a lower energy level without any) it has a higher energy level than 3d
so electrons are lost from 4s first
rules for subshells when forming ions
electrons are always lost from the highest energy subshell
first ionisation energy defintion
energy needed to remove one mole of electrons from one mole of atoms
in their gaseous state
to form a mole of 1+ ions also in their gaseous state
first ionisation energy equation
X(g) -> X+(g) + e-
second ionisation energy definition
energy needed to remove one mole of electrons
from a mole of a gaseous 1+ ion
to form a 2+ ion also in their gaseous state
second ionisation energy equation
X+(g) -> X2+ (g) + 2e-