General Chemistry Atomic Structure & Periodic Trends Flashcards
What is the Heisenberg Uncertainty Principle?
The principle states it is not possible to know exactly where an electron is AND the momentum of the electron at the same time.
Explain Bohr’s Model of an atom in relation to electrons.
The bohr model shows a big gap between the first energy shell and the second shell. These gaps grow smaller as the shell number increases to infinity. Therefore, the energy differential is smaller as you increase to infinity.
Explain ground state and excited electrons.
Ground state electrons can be hit with energy such as UV and be “excited” to a higher energy level in a different shell.
The electron can return to ground state, the original shell, and will release a photon in the process.
What is Pauli’s Exclusion Principle?
The exclusion principle states that there can not be two electrons that share the same quantum numbers.
Compare the size between cations, neural elements, and anions.
Anions are larger because they have gained an extra electron, then neutral elements, and finally cations are the smallest.
What is ionization energy and what is the trend?
Ionization energy is the energy it takes to remove the outermost electron from an element. Half filled and fully filled valence elements are happy so it is harder to remove those electrons.
Ionization energy increases left to right
Ionization energy decreases up to down.
What is electron affinity and what is the trend?
Electron affinity is the energy released when an electron is added to a molecule.
Electron affinity increases left to right
Electron affinity decreases up to down.
What is electronegativity and what is the trend?
Electronegativity is the tendency for an element to attract electrons towards itself between a bond.
Electronegativity increases left to right
Electronegativity decreases up to down.
What is diamagnetic?
Diamagnetic elements have even paired electrons in their orbitals. Not just even numbers, but they have to have all their electrons paired. This causes these elements to not be magnetic.
What is paramagnetic?
Paramagnetic elements have unpaired electrons in their orbitals. This causes these elements to be magnetic.
Describe the characteristics of Alkali metals.
This group displays all the properties that metals show.
Form +1 ions
Strong reducing agents.
Extremely reactive, forms ionic compounds and hydrogen gas.
Describe the characteristics of Alkali earth metals
This group displays all the properties that metals show. Harder than alkali metals Form 2+ ions Strong reducing agents. Extremely reactive.
List the electromagnetic spectrum starting with AM frequency.
AM- FM- micro- infra- ROYGBV- UV- xray- gamma rays
What range of wavelengths does ROYGBV cover?
Red is 700 nm
Violet is 400 nm
What is Avagodro’s number?
6.03 * 10^ 23 molecules
What is an isotope?
An element with different amounts of neutrons.
Carbon 12 has 5 neutrons. Carbon 13 has 7 neutrons. Carbon 14 has 8 neutrons.
What are the characteristics of metals?
- In metals, electrons move with ease between the atoms which allows metals to be conductive material.
- Malleable (thin strips)
- Ductile (stretch)
- Form ionic (non covalent) oxides with oxygen, except BeO (covalent).
What are the characteristics of non metals?
- Diverse chemical behavior
- Form negative ions
- Form covalent oxides
Describe Group 14 elements
- Can form 4 covalent bounds with non metals.
2. Only carbon can form strong pi bonds.
Characterize Nitrogen
Normally neutral nitrogen (NH3, ammonia) has 3 bonds with 2 lone pairs.
Nitrogen can have 4 bonds, but will have a positive charge (NH4+, ammonium)
Do electrons from the 4s or 3d get taken first?
Electrons from the 4s orbital are taken because they are at a higher energy level and thus further away from the nucleus.
What are isoelectronic atoms? What is the size comparison?
Same number of electrons but different number of protons.
Example. 10 E, 10 P vs 10 E, 11 P.
More protons causes the atom to be smaller, so the second atom will be smaller.
Describe the atomic radius trend on the periodic table?
Atomic radius decreases going right due to proton increase
Atomic radius increases going down due to shell increase
Describe alpha decay
Alpha decay is the loss of a helium atom. Basically, you lose 2 protons and 2 neutrons, so a 4,2 loss. This means you’re going to change elements.
Describe the photoelectric effect.
Work function states a photon, with enough energy, can knock lose an electron causing it to be free. The energy needed to remove the electron is called the work function. The kinetic energy that the free electron has will be equal to the amount of energy need plus the kinetic energy of the incoming photon.
What is the work function?
The work function in the energy required to remove an electron from an atom. If the photon does not have the required work function energy, then the electron can not be removed from the atom.
Describe a graph for photoelectric effect with kinetic energy and frequency.
There is a minimum threshold required, therefore there must be a space in the x axis. It is a linear proportion other then that one fact.
Emission vs Absorption Spectra.
Emission shows bright lights on black page from shells of emission.
Absorption shows dark lines on colored page from shells of absorption.
How can you calculate the amount of product remaining for half life problems?
(.5)^n, where n in the half life.
