Unit 5 test Flashcards
What are electrons?
subatomic particles with a negative charge
Where are electrons?
In shells or energy levels that surround the nucleus of an atom
What did Bohr’s model show?
Negative electrons circle the positive nucleus at fixed distances called energy levels
What was Schrodinger’s theory?
Electrons travel in waves. Bohr’s model was wrong because he restricted the electrons to specific orbits.
What are orbitals?
Regions around the nucleus where electrons are most likely to be. These were identified by Schrodinger.
What kind of shapes did Schrodinger believe the orbitals were?
Spheres, peanuts, double peanuts, or flowers.
What is the quantum mechanical model?
Modern model that is also commonly called the electron cloud model. Each orbital around the nucleus resembles a fuzzy cloud. The darkest, densest areas of the cloud are where the electrons have the greatest chance of being.
What are energy levels?
fixed distances from the nucleus where electrons may be found.
True or false: as you go farther from the nucleus, electrons at higher levels have more energy.
trueeeeeeeeeeeeeeee
What are valence electrons?
electrons in the outermost energy level. They determine properties of the atom like how reactive they are.
what are principle energy levels and how are they like a parking garage?
on each level are “parking spots” for electrons. The orbitals are areas within a principle energy level that contain the parking spots, and each spot has a unique number.
What are the four orbital (sublevel) types?
s, p, d, f
how many electrons do each of the orbitals shapes hold?
s holds 2, p holds 6,, d holds 10, and f holds 14
What is the electron configuration of lithium (3)?
1s^2 2s^1
What is the Aufbau principle?
Each electron occupies the lowest energy orbital available.
What is the Pauli exclusion principle?
A maximum of 2 electrons can occupy a single orbital, but only if they have opposite spins.
What is Hund’s rule?
single electrons with the same spin must occupy each equal energy orbital before additional electrons can occupy the same energy level orbitals.
True or false: valence electrons can be transferred or shared in a reaction
TRUEEEEEEEEE
What is the Octet rule?
Atoms are most stable when they have 8 electrons in their outer (valence) shell. every atom tries to attain this arrangement. Atoms tend to gain, lose, or share electrons until they have 8 valence electrons
Why do noble gasses have no desire to react with other elements?
They have a full outer shell of 8 valence electrons
what is an electromagnetic wave?
waves that consist of vibrating electric and magnetic fields.
define electromagnetic radiation.
The transfer of energy by electromagnetic waves
How does an electromagnetic wave begin?
an electrically charged particle vibrates, causing a vibrating electric field, which in turn creates a vibrating magnetic field. The two vibrating fields form together into an electromagnetic wave.
What happens when electromagnetic waves strike matter?
they may be reflected, refracted, defracted, or absorbed.