Goals
1. Recognise the key properties, such as electronegativity, that we can understand from the periodic table.
2. Identify the periodic and non-periodic properties of chemical elements in the periodic table.
Contextualization
The Periodic Table is a fundamental tool in Chemistry, as it systematically arranges all known chemical elements to help us grasp their properties and behaviours. Over the years, significant contributions from scientists like Dmitri Mendeleev have shaped this table, which remains an essential reference in academic research and various industries. Grasping the Periodic Table is not just about theoretical knowledge; it has practical implications in areas like medicine, engineering, and technology. For example, in the electronics industry, silicon’s semiconductor properties are deeply rooted in its position on the Periodic Table.
Subject Relevance
To Remember!
Electronegativity
Electronegativity measures how strongly an atom attracts electrons in a chemical bond. It varies based on the element's position in the Periodic Table, increasing from left to right and from bottom to top.
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Definition: The ability of an atom to attract electrons in a chemical bond.
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Variation: Increases from left to right and decreases from top to bottom in the Periodic Table.
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Relevance: Influences the polarity of molecules and the reactivity of elements.
Atomic Radius
Atomic radius refers to the average distance between an atom's nucleus and its outermost electron shell. This distance changes across the Periodic Table, decreasing from left to right and increasing from top to bottom.
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Definition: Average distance between the nucleus and the outermost electron shell.
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Variation: Decreases from left to right and increases from top to bottom in the Periodic Table.
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Relevance: Affects the size of atoms and the distance between atoms in a chemical bond.
Ionization Energy
Ionization energy is the energy needed to remove an electron from an atom in the gaseous state. This energy also varies across the Periodic Table, increasing from left to right and decreasing from top to bottom.
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Definition: Energy required to remove an electron from an atom in the gas phase.
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Variation: Increases from left to right and decreases from top to bottom in the Periodic Table.
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Relevance: Influences how readily an atom can form cations.
Practical Applications
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Development of semiconductor materials for electronics, such as silicon, which relies on its position in the Periodic Table and its electronic characteristics.
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Creation of pharmaceuticals that utilise specific chemical elements based on their periodic properties, like electronegativity, to interact with biological targets.
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Production of metal alloys designed for specific traits, such as strength and durability, based on the periodic properties of the elements involved.
Key Terms
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Electronegativity: Measure of an atom's ability to attract electrons in a chemical bond.
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Atomic Radius: Average distance between an atom's nucleus and its outermost electron shell.
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Ionization Energy: Amount of energy needed to remove an electron from an atom in a gaseous state.
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Periodic Properties: Properties of elements that vary in a predictable manner across the Periodic Table.
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Non-Periodic Properties: Properties of elements that do not follow a predictable pattern in the Periodic Table.
Questions for Reflections
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How can the electronegativity of an element affect its properties within chemical compounds?
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In what ways can atomic radius influence an element's reactivity?
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Why is ionization energy a significant factor in the formation of ions?
Practical Application Challenge: Properties in Action
This mini-challenge is designed to reinforce your understanding of periodic and non-periodic properties by creating an interactive periodic table and examining its practical applications.
Instructions
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Form groups of 4-5 students.
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Utilise the cards that contain information about chemical elements (name, symbol, atomic number, electronegativity, etc.) supplied by the teacher.
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Arrange the cards on a large sheet of paper or poster board to construct a physical periodic table.
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Select a set of periodic properties (electronegativity, atomic radius, ionization energy) and highlight them creatively on the cards (for example, using colours or symbols).
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Each group should present their interactive periodic table, explaining their choices and how the periodic properties affect the behaviour of the elements.
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Discuss how the later-debated properties apply to real-life situations, such as selecting materials for electronic devices or innovating new chemical compounds.
