Definitions
Atomic number of an atom is equal to ______
The number of protons in its nucleus.
Who discovered electrons?
J.J. Thomson
What subatomic particles are contained within the nucleus?
Protons and Neutrons
What is the electron configuration of Sulfur (S)?
1s22s22p63s23p4
How many valence electrons does Sulfur (S) have?
6
The atomic mass of an atom is equal to the _______
total number of protons and neutrons.
What is the Pauli Exclusion Principle?
Two electrons in the same orbital must have opposite spins.
How many electrons are there in a neutral atom of sodium (Na)?
11 electrons
What is the electron configuration of Rubidium (Rb)?
1s22s22p63s23p64s23d104p65s1
How many valence electrons does Iron (Fe) have?
8
What is an ion?
An atom with a net charge due to the loss or gain of one or more electrons.
What is Hund's rule?
If there are more than one orbital at a particular energy level, one electron goes into each orbital before they double up.
How many neutrons are there in tungsten?
110 neutrons
Which element has the following electron configuration?
[Ar]4s23d10
Zinc (Zn)
How many valence electrons does Lead (Pb) have?
4
What is an isotope?
(Explain with # of p, n, and e-)
An isotope of an element contains the same number of protons and electrons, but different number of neutrons.
What is a difference between J.J. Thomson's and Rutherford's model of the atom?
Thomson's model = a positively charged bulk with negative electrons embedded (plum pudding model).
Rutherford's mode = a small, dense, positively charged nucleus with electrons outside the nucleus.
How many neutrons and electrons are there in As+1?
42 neutrons
32 electrons
What is the core notation of I-1?
[Kr]5s24d105p6
How many valence electrons does B-1 have?
8
Average atomic mass is _________
the weighted average masses of all the natural isotopes of an element by their abundance.
Name three ways that a proton is different from an electron.
A proton is positively charged, located in the nucleus of an atom, and its mass contributes to the atomic mass of the atom.
An electron is negatively charged, located outside the nucleus of an atom, and its mass does not contribute to the atomic mass of the atom.
Identify the element with mass number 238 and calculate the number of neutrons in that element.
Uranium.
# of n = 146
What is the core notation of Gold (Au)?
[Xe]6s24f145d9
With the wave mechanical model, valence electrons are defined all the electrons in the atom except does in the ____________ or ___________.
core notations and completely filled d- and f- orbitals