Chapter 2 Flashcards
Define Atomic mass
the average mass of the naturally occurring isotopes of an element
Define atomic radius
the distance from the nucleus to the outermost occupied electron orbital in an atom
State Aufbau principle
the procedure for assigning electrons to shells, subshells, and orbitals in the order of increasing energy.
What is Azimuthal quantum number ?
the number designation (l) of an electron subshell.
What is a closed shell?
a valence shell in an atom that has the maximum number of electrons allowed by the Pauli Exclusion Principle.
What is electron affinity?
the amount of energy released when an electron is added to a neutral atom in the gas phase
What is electronegativity ?
a measure of the tendency of an atom to attract electrons from another atom in a chemical bond
What is electron configuration?
What is an excited state?
higher energy state of an atom arising from the absorption of energy and the transition of electrons to higher orbitals.
Define : Principal quantum number
the number designation (n) of an electron shell. Proton a positively charged particle present in all atomic nuclei.
What is meant by : quantized ?
a quantity that is restricted to certain allowed values
How many naturally occurring elements are there?
98
What three particles make up an atom and what are their charges?
- Proton > positively charged
- Neutron > unchanged
- Electron > negatively charged
Where is the majority of the mass of an atom located?
Nucleus
Where is the majority of the volume of an atom located?
Electrons in their orbitals
What is the atomic number of an atom equal to?
Number of protons in the nucleus
What is the mass number of an atom equal to?
Number of protons + number of neutrons
What are the atomic symbols of the following elements: (a) boron, (b) antimony, (c) silver, (d) tungsten, (e) astatine, (f) iron?
a. B
b. Sb
c. Ag
d. W
e. At
f. Fe
What are the names of the following elements:(a) Cl , (b) Cu , (c) Au , (d) Tl , (e) Na , (f) Rn?
a. Chlorine
b. Copper
c. Gold
d. Thallium
e. Sodium
f. Radon
What are isotopes?
Elements that have the same number of protons but different number of neutrons
How atomic mass different from mass number?
Mass number is equal to the number of protons and neutrons in the nucleus of an atom
Atomic mass average mass of all naturally occurring isotopes
What determines the chemistry of an atom?
It’s electrons
What is meant by electrons being quantized?
The energy of electrons is being restricted to certain allowed values
What is the quantum number that designates an electron shell? What is its letter designation?
Principle of quantum number (n)
What is the quantum number that designates an electron subshell? What is its letter designation?
Azimuthal quantum number (l)
What is the quantum number that designates the spatial orientation of an orbital? What is its letter designation?
Magnetic quantum number (m)
What is the Pauli Exclusion Principle?
No two electrons can have the same four quantum numbers
List the four quantum numbers, their letter designations, and their allowed values.
- Principle of quantum number ….(n) …. 0,1,2,3..
- Azimuthal quantum number …. (l) …. -1,0,1..
- Magnetic quantum number …. (m) …. +l , 0 ,-l
- Spin quantum number …. (s) …. -½ , + ½
What is the ground state of an atom?
Electronic configuration with the lowest possible energy
What creates an atomic excited state?
Absorption of energy causing an electron to move to a higher energy orbital
What is released when an electron falls from a higher orbital to a lower one?
Energy inform of light
What is the Aufbau principle?
Procedure of assigning electrons into shells , sub shells and orbitals in oder of increasing energy
What is Hund’s Rule?
Electrons will occupy orbitals individually before occupying them in pairs
List the electron subshells in the order of increasing energy.
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