To solve the problem, we need to understand the task associated with the periodic table image you uploaded. Since the task is not explicitly stated in your question, I will infer a common type of problem related to the periodic table and provide a solution.
Assumed Task:
Identify the element with atomic number 17 and describe its properties.
Solution:
1.
Identify the Element:
- The periodic table shows elements arranged by their atomic numbers.
- The element with atomic number 17 is located in the 3rd period and the 17th group.
- From the table, the element with atomic number 17 is
Chlorine (Cl).
2.
Properties of Chlorine (Cl):
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Atomic Number: 17
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Atomic Mass: Approximately 35.45 u
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Group: 17 (Halogens)
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Period: 3
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Electron Configuration: \(1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^5\)
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Valence Electrons: 7 (in the outermost shell)
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State at Room Temperature: Diatomic gas (\(Cl_2\))
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Color: Pale green-yellow
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Physical State: Gas
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Reactivity: Highly reactive due to its high electronegativity (3.16) and tendency to gain one electron to achieve a stable electron configuration.
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Uses: Chlorine is widely used in water purification, disinfection, production of plastics (e.g., PVC), and as a bleaching agent.
3.
Explanation:
- Chlorine is a member of Group 17, also known as the halogens. Halogens are highly reactive nonmetals that readily form compounds with metals.
- Its position in the periodic table (period 3, group 17) indicates it has 7 valence electrons, making it one electron short of a stable octet. This explains its high reactivity.
- Chlorine's diatomic nature (\(Cl_2\)) means it exists as pairs of chlorine atoms in its elemental form.
Final Answer:
The element with atomic number 17 is
Chlorine (Cl). It is a highly reactive, pale green-yellow gas found in Group 17 (halogens) and Period 3 of the periodic table. Its electron configuration is \(1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^5\), and it is widely used in water purification, disinfection, and industrial applications.
\[
\boxed{\text{Chlorine (Cl)}}
\]
Parent Tip: Review the logic above to help your child master the concept of printable periodic table with names.
