Atomic Structure
The atomic number (Z number) is equal to what?
The number of protons an element has.
An isotope has a different number of _____.
Neutrons
Who wrote the four postulates that are called "The First Atomic Theory".
Dalton
An ion has a different number of ______.
Electrons
Why can we not mass atoms in grams?
How many electrons does Xe (Xenon) have?
54
How many neutrons does Gold-198 have?
119
Who described the atom as a "marble-like" sphere?
Democritus
A cation has a __________ charge and an anion has a ________ charge.
positive, negative
How many places past the decimal do we round average atomic mass?
Two places past the decimal.
How many neutrons does Polonium-211 have?
127
Isotopes all have the same mass number.
False, due to their neutrons being different. The mass number will be different.
Who designed the Planetary Model?
Niels BOHR
How many electrons does N-3 have?
10
What is the formula for calculating average atomic mass?
E(mass)x(abundance in decimals)
What is the mass # of Sulfur if it has 17 neutrons?
33
If an element has a mass number of 42 and 18 protons, what is the name of the isotope?
Argon-42
What did Rutherford's "Gold Foil Experiment" discover?
There is a positively charged nucleus in the atom.
OR
The atom has a LOT of empty space.
How many electrons does Ba2+ have?
54
There are two isotopes of iron, Fe-56 and Fe-57.
Fe-56 has a 78.34 % abundance, and Fe-57 has a 21.66%. Find the average atomic mass. Remember to round correctly.
56.22 amu
What is the isotopic notation for Magnesium-25?
25
Mg
12
How many electrons does Aluminum-28 have?
13
What did JJ Thompson's cathode ray tube experiment discover? (This one has two parts to the answer)
That particles called "electrons" exist and they are negatively charged.
If an element has 8 protons and 6 electrons, what element is it and what is its charge?
O2-
Calculate the estimated average atomic mass of magnesium if magnesium exists naturally as 60.63% Mg-24, 34.04% Mg-23, and the rest is Mg-25. What is the average atomic mass?
23.71 amu