DAT General Chemistry exam with complete solutions.
4 views 0 purchase
Course
DAT
Institution
DAT
Atomic Number
number of protons found in that atom; low number; (Z)
Mass Number
Protons + Neutrons; high number; (A)
Previous
Play
Next
Rewind 10 seconds
Move forward 10 seconds
Unmute
0:00
/
0:15
Full screen
Brainpower
Read More
Atomic Mass
relative mass of that atom...
DAT General Chemistry exam with
complete solutions
Atomic Number - ANSWER-number of protons found in that atom; low number; (Z)
Mass Number - ANSWER-Protons + Neutrons; high number; (A)
Atomic Mass - ANSWER-relative mass of that atom compared to the mass of a carbon-
12 atom (which is set at 12.00); measured in amu;
1 amu = - ANSWER-1.66x10^-24
Atomic Weight - ANSWER-weight (g) of one mole (mol) of a given element (g/mol); the
weighted average of all the masses (not the weights) of an element, weighted according
to the natural abundance of the isotopic species of an element
Isotope - ANSWER-multiple species of an atom with same number of protons and a
different number of neutrons (different mass numbers); generally exhibit same chemical
properties
Ernest Rutherford - ANSWER-1911; gave experimental evidence that an atom has a
dense, positively charged nucleus that accounts for a small portion of the volume of the
atom
Max Planck - ANSWER-developed first quantum theory; 1900; proposed that energy
emitted as electromagnetic radiation from matter comes in discrete bundles called
quanta; E=hv (h-Planck's constant)
Planck's constant - ANSWER-6.626x10^-34 J*s
The Bohr Model of the Atom - ANSWER-developed 1913 model of H atom using
Rutherford and Planck's findings; H atom has central proton, electron travels around it in
a circular orbit; centripetal force acting on the electron as it revolved around the nucleus
, was the electrical force between the positively charged proton and negatively charged
electron; quantized angular momentum so it changed in discrete amounts in relation to
the quantum number (L=nh/2pi) n=quantum number h=Planck's constant; from this
Energy of an electron: E=-Rh/n^2, Rh=Rydberg constant 2.18*10^-18 J/electron
Rydberg Constant - ANSWER-2.18 x 10^-18 J/electron
Smaller orbit of electron the... - ANSWER-lower the energy state
What is the Bohr Model used for? - ANSWER-used to explain the atomic emission
spectrum and atomic absorption spectrum of hydrogen; because these spectrum are
not the continuous spectrum that classical physics would expect, they are line spectrum
Balmer Series - ANSWER-4 spectral lines that appear in the visible light region when a
hydrogen atom undergoes a transition from energy levels n>2 to n=2.
Lyman Series - ANSWER-Set of spectral lines appearing in the UV region when a
hydrogen atom undergoes a transition from energy levels n>1 to n=1.
Heisenberg Uncertainty Principle - ANSWER-impossible to determine the momentum
and position of an electron simultaneously; means if the momentum of an electron is
being measured accurately, its position will change and vice-versa
Pauli exclusion principle - ANSWER-no 2 electrons in any given atom can possess the
same set of four quantum numbers (n, l, ml, ms)
Energy state of an electron - ANSWER-the position and energy of an electron described
by its 4 quantum numbers (n, l, ml, ms)
quantum number n - ANSWER-"principal quantum number"; gives info about the size of
the orbital; bigger n is, the bigger the radius of the orbital, the bigger the energy of the
orbital; Max number of electrons in an energy level = 2n^2
quantum number l - ANSWER-"Azimuthal (angular momentum) quantum number";
gives info about the shape of the orbital; value of l = 0 to n-1 ; l=0=s; l =1=p; l=2=d;
l=3=f; Max number of electrons that can exist in a subshell= 4l +2; greater the value of l,
the higher the energy of the subshell, but subshell energies from different principal
energy levels may overlap
quantum number ml - ANSWER-"Magnetic Quantum number"; gives info about the
orientation of an orbital; value of ml = l to -l (includes 0);
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller tuition. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.99. You're not tied to anything after your purchase.
