Atomic Theory and the Periodic Table Review
What are the contributions of the following people to the atomic model? For those that resulted in a revision to the model. Draw the model they proposed.
Democritus- originally named atom; atom model is solid homogenous sphere
Dalton- proposed the atomic theory, atom model is solid homogeneous sphere
Thomson- proved the existence of negative particles through work with cathode ray tubes; atom model had negative particles embedded in positive matrix (also called plum pudding model)
Rutherford- proved the existence of the nucleus with gold foil experiment; atom model had positive particles in a nucleus surrounded by electron
Chadwick- discovered the neutron
Bohr- atom model had a nucleus of protons and neutrons surrounded by electron in fixed orbits like planets orbiting the sun
Give the charge and location of each of the subatomic particles.
Particle Charge Location
Proton __+______nucleus______
Neutron __0______nucleus______
Electron __-______orbiting nucleus______
Define the following:
Atomic Number- number of protons in an atom
Mass Number- number of particles in the nucleus (protons + neutrons) in a particular atom
Atomic Mass- average mass of all the naturally occurring isotopes of an element according to their abundance
Isotope- atoms of the same element that differ in their number of protons (and so also differ in their mass number)
Ion- atom with a charge because of the number of protons and electrons are unequal
Cation- a positively charged ion; occurs when a neutral atom loses electrons
Anion- a negatively charged ion; occurs when a neutral atom gains electrons
Calculate the number of protons, neutrons, and electrons of the following isotopes.
Isotope # of Protons # of Neutrons # of Electrons
Hydrogen-3 1 2 1
Hydrogen-2 1 1 1
Calcium-40 20 20 20
Copper-63 29 34 29
Iodine-127 53 74 53
Barium-137 56 81 56
Write the nuclear symbol for each of the isotopes in the previous problem
_3H__ __2H __ ___40Ca __ ___63Cu __ ___127I __ ___137Ba ___
Calculate the number of protons, neutrons, and electrons of the following ions.
Ion # of Protons # of Neutrons # of Electrons
37Cl- 17 20 18
22Na+ 11 11 10
28Mg+2 12 16 10
14N-3 7 7 10
Name each of the following ions. Multivalent ion are in bold.
Fe+3 __iron (III) ion______
S-2 __sulfide ion______
Li+ __lithium ion______
I- __iodide ion______
Calculate the average atomic mass of the following problems.
Silver (Ag) is found as two isotopes (silver-107 and silver-109). What is the average atomic mass if the abundance of silver 107 is 51.86%?
107 x 0.5186 = 55.4902
109 x 0.4814 = 52.4726
55.4902 + 52.4726 = 107.96 amu
Iron has four isotopes (listed with their abundances below). Calculate the average atomic mass.
Iron-54 5.90%
Iron-56 91.72%
Iron-57 2.10%
Iron-58 0.280%
54 x 0.0590 = 3.186
56 x 0.9172 = 51.3632
57 x 0.0210 = 1.197
58 x 0.00280 = 0.1624
3.68 + 3.666 + 35.232 + 2.695 = 55.91 amu
Who is the “father” of the period table? Mendeleev
The modern periodic table has the elements arranged by their _atomic number___ forming columns called _groups or families___ and rows called _periods______.
What group numbers are each of the following?
Alkali metals- 1
Alkaline earth metals- 2
Halogens- 17 (7A)
Nobel gases- 18 (8A)
Transition elements- 3-12
Name at least three characteristics of metals and nonmetals.
Various (see notes)
For each of the following elements, determine if it is a metal, metalloid, or non-metal.
Na __metal______
Si __metalloid______
N __non-metal______
Ar __non-metal______
U __metal______
Pb __metal______
List the seven diatomic elements. N, O, F, Cl, Br, I