Questions and Answers
How do chemists use the periodic law to classify elements?
The periodic law states that there is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number.
What determines the vertical arrangement of the periodic table? Horizontal?
What property do the noble gases share?
They are all extremely unreactive.
Why is beryllium, a highly reactive metal, placed in group 2?
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Describe the development of the modern periodic table.
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How does shielding effect their atomic size?
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Study Notes
Periodic Law and Classification of Elements
- Periodic law indicates a periodic repetition of chemical and physical properties when elements are arranged by increasing atomic number.
- This law enables scientists to easily integrate newly discovered elements into the periodic table.
Arrangement of the Periodic Table
- Vertical arrangement corresponds to groups (columns) of elements with similar properties.
- Horizontal arrangement represents periods (rows) reflecting the energy levels of electrons.
Noble Gases
- Noble gases are characterized by their extreme lack of reactivity, making them unique in the periodic table.
Beryllium Classification
- Despite being highly reactive, beryllium is classified in Group 2 as an alkaline earth metal.
Development of the Modern Periodic Table
- Antoine Lavoisier is recognized for early classification efforts of elements.
- John Newlands organized elements by increasing atomic mass; introduced the Law of Octaves.
- Dmitri Mendeleev created the first widely accepted periodic table, also based on increasing atomic mass, allowing for predictions of undiscovered elements.
- Henry Moseley corrected Mendeleev's periodic table by organizing elements according to increasing atomic number, resolving prior inconsistencies.
Atomic Size and Shielding Effect
- The shielding effect influences atomic size by reducing the effective nuclear charge felt by outer electrons, affecting how tightly electrons are held to the nucleus.
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Description
Explore the key concepts of the periodic law and its implications for the modern periodic table in this flashcard quiz. These cards cover the classification of elements and their properties as they relate to atomic number and chemical behavior. Perfect for students studying chemistry or preparing for exams.
