Structures and Properties of Matter Flashcards
How are Thomson’s and Rutherfords models of the atom similar and different?
Like Thomson, Rutherford still believed that atoms contained negatively charged electrons. The difference was, unlike the plum pudding model, where those atoms simply floated in “soup,” Rutherford believed they orbited the central nucleus just as planets orbit the sun.
What is an energy level? And explain the difference between ground state and excited state.
An energy level is the specific energies that electrons can have when occupying specific orbitals
An atom in its lowest possible energy state (ground state) can be excited to a higher state only if energy is added equally to the difference between the two levels.
What was Planks contribution to the Quantum Mechanical atom?
Plank was able to find a mathematical formula that fits the empirical data, if light was treated like a particle instead of a wave.
What is the photoelectric effect?
The photoelectric effect is when a photon hits an electron on a metal surface, it is then emitted.
What is an orbital? Describe the shape of an S and P orbital.
An orbital is an energy level around the nucleus of an atom that can hold electrons.
The S orbital is simply a sphere of electron density and
can hold two electrons, as long as they have different spin quantum numbers.
The P orbitals each have one angular node and each orbital can accommodate two electrons (with opposite spins), which gives the p orbitals a total capacity of six electrons.
What do the four quantum numbers ( n, l, ml, ms) determine
n- Size of the orbital
l- Shape of the orbital
ml- Orientation of the orbital
ms- Electron spin
Why does is make sense that electron configurations represent atoms in their ground state and not their many excited states?
Because the ground state is the most common. If you were to represent atoms in their excited states it could take awhile.
List the 3s,5s,2p,4p,3d,5d orbitals in order from lowest energy to highest energy
Lowest- 2p, 3s, 4p, 5s, 5p, 5d -Highest
1S2 2S2 2P4 represents?
Oxygen
What does delocalized mean?
It means that electrons are shared among more than two atoms in a molecule.
Metallic bonds result from the attraction between the nuclei of metal atoms and the sea of delocalized electrons surrounding them.
Explain how single bonds form, based on quantum mechanical concepts
Atoms share one pair of electrons where the bond forms. Meaning its a covalent bond.
Explain the presence of sigma and pi bonds in molecules
Sigma- Overlap of hybrid orbitals of the central atom
Pi- Overlap of unhybridized “p” orbitals of the central atom
What are 2 ways a non-polar molecule can temporarily become a dipole
When two non-polar molecules comes closer to each other. The negative part (electrons) of one molecule attract the positive part (nucleus) of another molecule. As a result, two dipoles are induced.
How have medical diagnostics benefitted from an improved understanding of the atomic structure (3 examples)
Dalton’s atomic theory showed the basic structure of the atom which helped because subatomic particles are currently used in the fields of cardiology, cardiovascular surgery, radiology and nuclear medicine for diagnoses and therapies
The special properties of water resulting from hydrogen bonding
Water’s high surface tension is due to the hydrogen bonding in water molecules. Water also has an exceptionally high heat of vaporization
