Class 1 Flashcards
What determines the atomic number?
The number of protons
What determines atomic mass?
Protons + neutrons
What determines the element?
Atomic number (protons)
What is the effective charge of an electron?
ZERO!
The distance between orbits decreases as distance from the nucleus ________.
increases
Thus, the energy “gap” between the lower steps is higher because they are farther apart
Energy increases with _______ distance from the nucleus.
increasing
What happens when an electron drops from a higher orbit to a lower one?
Is this an endothermic or exothermic process?
Energy is released as a photon.
Exothermic
How can you remember the order of the electromagnetic spectrum?
G randmas X rated U nderpants Are Visible I n M y Room
Gamma X ray UV Visible light (ROYGBIV backwards) Infrared Microwave Radio
Gamma rays = high energy and high frequency, short wavelengths
Radio waves = low energy, low frequency, long wavelengths
What is the equation for the energy of a photon?
E = hf = hc/lambda
where h = plancks constant
f= frequency
c = speed of light (3x10^8)
and lamba = wavelength
Note that energy and frequency are directly related but energy and wavelength are INVERSELY related.
How are energy and frequency related?
Directly
How are energy and wavelength related?
Inversely
Energy _____ with complexity of orbital shape.
So what is the hierarchy?
increases
s
The first d block acts like what row?
3
The first f block acts like what row?
4
What does the Pauli principle say?
No two electrons can be identical.
What does the Aufbau principle say?
Energy levels will get filled (with electrons) starting with the lowest energy levels (n=1)
Similarly, the highest energy electrons will get removed first.
What is a tricky thing about electron configuration of 4s3d elements?
Even though 3d is higher in energy, 4s electrons will be removed first because they are the VALENCE electrons.
What does Hund’s rule say?
Electrons will fill up all orbitals singly before pairing
What does diamagnetic mean?
All electrons are paired up
What does paramagnetic mean?
Some or all electrons are unpaired.
What is the electron configuration of Chromium? Why is this anomalous? What is another example?
{Ar}4s1 3d5
3d5 is a half-filled subshell which is particularly stable. Because of this it pulls off an electron from 4s2 to reach this stage. If it hadn’t done this it’d be 4s2 3d4 which is less stable.
The other example is copper! it will be 4s1 3d10 to reach a completely full subshell.
What is the most stable group and why?
The noble gases which are very non-reactive because they have full octets.
What is the first group of the periodic table called?
Alkali metals
What is the second group of the periodic table called?
Alkali earth metals
What is a mnemonic for the diatomic atoms?
Br I N Cl H O F
B2 (bromine) I2 (iodine) N2 (nitrogen) Cl2 (chlorine) H2 (hydrogen) O2 (oxygen) F2 (fluorine)
What group are the halogens?
Second farthest right (next to noble gases)
What do core electrons do to valence electrons? What can calculate based on this?
Shield them from the full nuclear charge. Z effective is equal to core charge - electrons in inner shell.
As you move left to right on the periodic table, Z effective ______.
Increases
As you move left to right on the periodic table, Fe ________. Why?
Increases. Because no core electrons are added but Z effective increases
What does Z effective do as you move down the periodic table?
Virtually nothing because protons and core electrons are being added in equal number.
What does Fe do as you move down the periodic table?
Fe decreases because Z effective isn’t really changing, but orbital size is getting bigger.
Overall, the force on valence electrons does what across the periodic table?
Increases up and to the right
Atomic radius _______ moving left to right across the periodic table
decreases (because Fe is increasing and thus pulling the electrons in tighter)
Atomic radius _______ moving top to bottom down the periodic table
increases (because Fe is decreasing and thus electrons aren’t pulled in as tightly).
Overall, the ionization energy does what across the periodic table?
Increases up and right
just like Fe, duh! If they’re pulled in more tightly, it’s hard to snatch em!
Electron affinity does what across the periodic table?
Increases (more negative) up and to the right
What is electronegativity?
The ability to attract electrons
Electronegativity does what across the periodic table?
Increases up and right
What mnemonic helps you remember the relative electronegativity of the top right corner?
F > O > N > Cl > Br > I > S > C > H
Higher electronegativity = ________ acidity
higher
Overall, acidity does what across the periodic table?
increases down and to the right
What type of shells are extra stable?
Closed shell.
i.e. things that end in s2, p6, d10.
What is the concentration of I- ions in a 0.20 M solution of magnesium iodide?
The concentration of I- ions in a 0.20 M solution of magnesium iodide is 0.40 M.
Since the empirical formula for magnesium iodide is MgI2, two moles of dissolved I- result from each mole of dissolved MgI2. Therefore, if [MgI2] = 0.20 M, then [I-] = 2(0.20 M) = 0.40 M.
What is beta decay?
Beta decay (β–) results in the conversion of a proton to a neutron and an emitted beta particle.
