Unit 6 Supplemental Problems Key 311 1 
Supplemental Questions
1. A newer form of the periodic table has been established, but is not universally used at this time. Go to http://www.sciencenews.org/view/generic/id/67938/description/Periodic_table_gets_some_flex and read the article to answer the following questions:
a. What has been added to the new table?
The atomic weights of oxygen, hydrogen, lithium, boron, carbon, nitrogen, silicon, sulfur, chlorine and thallium are now be expressed as intervals.
b. Why is this addition important?
Ratios of isotopes will differ depending on their source (air, biological systems, earth, etc.). The relative abundance of isotopes can help scientists figure out what the source of the element is. Currently the isotopic abundances used to determine atomic mass are fixed. For the reason stated above, they should not be fixed.
2. Examine John Newland’s periodic table developed in 1864 (http://chemistry.tutorvista.com/inorganic-chemistry/law-of-octaves.html) to answer the following question.
Like our modern periodic table, the arrangement of elements in Newland’s table exhibited periodicity. The periodicity of Newland’s table is described by the Law of Octaves.
a. What does the Law of Octaves assert?
When elements (during the time of Newlands) were arranged according to atomic mass, the first and eighth elements were similar in their chemical and physical properties.
b. Why, in comparison, do the chemical properties of elements in the modern periodic table repeat every ninth element?
The Noble gases were not present in Newlands’ table.
3. What is the difference between the IUPAC, American and European group designations of the representative and transition elements in the periodic table. The following site might be helpful. http://www.webelements.com/periodicity/group_number/
IUPAC: Groups are numbered from 1 to 18
American: Representative element groups are labeled 1A-8A Transition element groups are labeled 3B, 4B, 5B, 6B, 7B, 8B (3 groups) 1B and 2B
1. A newer form of the periodic table has been established, but is not universally used at this time. Go to http://www.sciencenews.org/view/generic/id/67938/description/Periodic_table_gets_some_flex and read the article to answer the following questions:
a. What has been added to the new table?
The atomic weights of oxygen, hydrogen, lithium, boron, carbon, nitrogen, silicon, sulfur, chlorine and thallium are now be expressed as intervals.
b. Why is this addition important?
Ratios of isotopes will differ depending on their source (air, biological systems, earth, etc.). The relative abundance of isotopes can help scientists figure out what the source of the element is. Currently the isotopic abundances used to determine atomic mass are fixed. For the reason stated above, they should not be fixed.
2. Examine John Newland’s periodic table developed in 1864 (http://chemistry.tutorvista.com/inorganic-chemistry/law-of-octaves.html) to answer the following question.
Like our modern periodic table, the arrangement of elements in Newland’s table exhibited periodicity. The periodicity of Newland’s table is described by the Law of Octaves.
a. What does the Law of Octaves assert?
When elements (during the time of Newlands) were arranged according to atomic mass, the first and eighth elements were similar in their chemical and physical properties.
b. Why, in comparison, do the chemical properties of elements in the modern periodic table repeat every ninth element?
The Noble gases were not present in Newlands’ table.
3. What is the difference between the IUPAC, American and European group designations of the representative and transition elements in the periodic table. The following site might be helpful. http://www.webelements.com/periodicity/group_number/
IUPAC: Groups are numbered from 1 to 18
American: Representative element groups are labeled 1A-8A Transition element groups are labeled 3B, 4B, 5B, 6B, 7B, 8B (3 groups) 1B and 2B