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The Modern Periodic Table. 9.How is a keyboard an example of a periodic pattern?  On a keyboard there is a repeating pattern of notes. The scale repeats.

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Presentation on theme: "The Modern Periodic Table. 9.How is a keyboard an example of a periodic pattern?  On a keyboard there is a repeating pattern of notes. The scale repeats."— Presentation transcript:

1 The Modern Periodic Table

2 9.How is a keyboard an example of a periodic pattern?  On a keyboard there is a repeating pattern of notes. The scale repeats at regular 8-note intervals.

3 10.How are elements arranged in the modern periodic table?  In the modern periodic table the elements are arranged by increasing atomic number.

4 11.Why didn’t Mendeleev arrange the elements like they are in the modern periodic table?  Mendeleev developed his periodic table before the discovery of protons. He didn’t know that each element has a unique number of protons.

5 12.Please describe what a “period” is on the periodic table.  Each row in the periodic table is called a period.

6 13.According to the periodic table at the top of page 131, how many elements does period 7 have?  Period 7 has 32elements:  Spaces have been left for those that haven’t been discovered (synthesized)

7 14.Why does the number of elements per period differ?  The number of elements per period varies because the number of available orbitals increases from energy level to energy level.

8 15.Please explain what a “group” is on the periodic table.  Each column on the periodic table is called a group.

9 16.What do elements in the same group have in common?  Elements within a group have similar properties.

10 17.An element’s electron configuration determines its __________ properties.  Chemical  Chemical properties = reactivity & flammability

11 18.Please explain the periodic law.  Periodic law refers to a pattern of repeating properties  Members of a group in the periodic table have similar properties.

12 19.Look at page What is the first element in group 2A?  Be = Beryllium

13 20.What is the definition of an atomic mass unit (amu)?  An amu is defined as one twelth the mass of a carbon-12 atom

14 21.Please explain what a weighted average is.  In a weighted average some values are more important than other values.  E.g. grades – 60% tests, 25% labs, 15% daily work

15 22.How are weighted averages related to mass numbers (atomic mass)?  Atomic mass depends on the distribution of an elements isotopes in nature.  Those isotopes that occur in higher numbers naturally are given more “weight” in the average.  E.g. grades – test scores are weighted more heavily than labs

16 23.What are 3 ways that the periodic table classifies elements?  Metals  Nonmetals  Metalloids

17 24.What are 3 properties of metals?  Good conductors of electricity and heat  Malleable  Ductile

18 25.What is one distinctive property of the transition elements?  The transition elements have the ability to form compounds with distinctive colors  E.g. colored glass  E.g. Black Hills gold

19 26.What are 2 properties of non-metals?  Poor conductors of heat & electricity  Low boiling points so mostly gases at room T  If solid at room T then brittle

20 27.What are metalloids?  Metalloids are elements with properties that are between those of metals and nonmetals  A metalloids ability to conduct electric current depends on T

21 28.What happens to elements as you move from left to right across the periodic table?  Across a period from left to right, the elements become less metallic and more nonmetallic in their properties.


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