chemistry unit 1 Flashcards
explain how line spectra supported Bohr’s understanding of the atom
it supported Bohr’s understanding that atoms have energy levels and that energy levels can change, either going up or down. and cant be between levels. Line spectra supports this because it shows that after a atom is excited it will release energy and return to ground state by emitting certain wavelengths of visible light. In line spectra you will see lines of light caused by the release of energy, they represent energy levels and change in energy levels.
difference between Bohr model and electron cloud
Bohr’s model is only 2D, electrons move at constant speed in fixed orbits around the nucleus
electron cloud is a 3D model showing the most likely location of electrons in a atom. the electron cloud represents all the orbitals in the atom.
What is electron configuration
how electrons are arranged around the nucleus, determines chemical behaviour of elements
why are electrons in higher energy levels more available for bonding
they aren’t as attracted to the nucleus
what are the 4 sublevels and their amount of orbitals and their shape
S=1 sphere
P=3 dumbbell
D=5 clover
F=7 flower
HOW MANY ELECTRONS CAN BE IN EACH ORBITAL
2
electron configuration for chlorine
Cl 1s2 2s2 2p6 3s2 3p5
condensed electron configuration for chlorine
(Ne) 3s2 3p5
what makes a element more metallic
its ability to lose electrons more willingly
what causes outer electrons to not be as attracted to the nucleus
electron shielding
why does radius decrease across a period
the number of protons increase, this increases the attractive pull of the nucleus to its electrons
what is ionization energy
amount of energy needed to remove an electron
what is electronegativity
measure of how willingly an atom can attract a bonding pair of electrons
differ between ionic. polar and non polar bonds
ionic is the transfer of valence electrons, from metal to a non metal
non polar is the equal sharing of valence electrons between 2 atoms
polar is the non equal sharing of valence electrons between 2 atoms, giving each atom a partial charge
how do you represent each type of bond(+ polyatomic)
ionic- electron dot
non polar- lewis structure
polar lewis structure( dipoles)
Polyatomic-lewis or electron dot with brackets and charge( no dipoles)
what are the four exceptions to the octet rule
too few electrons
too many electrons
odd number of electrons
coordinate bonds
what vsper shapes tend to be non polar
linear, trigonal planar, tetrahydral
NOT ALWAYS
WHAT SHAPE IS ALWAYS POLAR
BENT
what do lone pairs cause and why
they cause smaller bonding angles for bonding pairs
because they are closer to the nucleus they take up more bonding space and repel more strongly then bonding pairs, so they push the bonding pairs closer together
what does polarity in a molecule determine
whether or not electrons are shared equally in the molecule
what are traits of a polar molecule
asymmetrical
0.4-1.7
lone pair
different surronding atoms
dipoles dont cancel out creating dipole moment
traits of non polar molecule
always symetrical
0-0.4
dipoles cancel out
differ between intra and inter molecular forces
intra are within the molecule and a lot stronger
inter are between molecules and a lot weaker
what are changes in state due to
changes in intermolecular forces
differ between LD DD and HB
LD- the weakest of them all, happens when electrons are on same side of molecule, all molecules experience, strenght increase with electron amount increase
DD- when dipoles of polar molecules postion their positive and negative ends near eachother, strength increase with electronegativity increase
HB- type of DD, when hydrogen bonds with fluorine, oxygen, or nitrogen
why are IMF’s important
many physical properties LIKE bp, fp, sf, v, vp are dependent on IMF
when IMF is stronger will the boiling point increase or decrease
increase
what trend is opposite out of bp, fp, sg, v and vp and why
vapour pressure, because when the IMF is stronger the vapour pressure will decrease
what are energy levels
areas at specific distances from the nucleus where electrons are found
what causes electrons to change energy levels
Energy such as heat or electricity
how do electrons release energy
by emitting wavelengths of light, the light from line sprectra
in what way do electrons fill orbitals
to minimize energy of atom, fill closer sublevels first
when adding superscripts of electron configurations what should it equal
atomic number, amount of electrons
compare cations and anions to there counterpart
ANIONS, get larger because there is a greater negative charge and aren’t attracted as strongly towards the nucleus
CATIONS, get smaller as there is less electrons the nucleus attracts the electrons closer
what is electron shielding
when inner electrons reduce the nucleus charge from outer electrons
