The Modern Periodic Table Is Shown Below. Answer The Following Questions:(A) हिलियमलाई पेरियोडिक तालिकाको समूह 18 राख्नुको कारण के हो? Why Is Helium Placed In Group 18 In The Periodic Table?एल्मुनियम र ब्रोमिनबिच रासायनिक प्रतिक्रिया हुँदा बन्ने
Introduction
The modern periodic table is a tabular arrangement of the known chemical elements, organized by their atomic number (number of protons in the nucleus), electron configuration, and recurring chemical properties. The periodic table is a powerful tool in chemistry, allowing us to predict the properties and behavior of elements and their compounds. In this article, we will explore the reasons behind the placement of Helium in group 18 of the periodic table.
The Periodic Table: A Brief Overview
The periodic table consists of 118 known elements, arranged in a grid of rows and columns. The rows are called periods, and the columns are called groups or families. The elements in each group exhibit similar chemical properties due to the same number of electrons in their outermost energy level. The elements in each period exhibit similar chemical properties due to the same number of electron shells.
Helium: A Noble Gas
Helium (He) is a noble gas, which means it is a member of group 18 of the periodic table. The noble gases are a group of elements that are chemically inert, meaning they do not readily react with other elements to form compounds. The noble gases are:
- Helium (He)
- Neon (Ne)
- Argon (Ar)
- Krypton (Kr)
- Xenon (Xe)
- Radon (Rn)
Why is Helium Placed in Group 18?
Helium is placed in group 18 of the periodic table because of its electron configuration. The electron configuration of an element is the arrangement of its electrons in its atomic orbitals. The electron configuration of Helium is:
1s²
This means that Helium has two electrons in its 1s orbital, which is the innermost energy level. The 1s orbital is a s-orbital, which means it is spherical in shape and can hold a maximum of two electrons.
The Octet Rule
The octet rule states that atoms tend to gain, lose, or share electrons to achieve a full outer energy level, which consists of eight electrons. This is known as a stable configuration. The noble gases, including Helium, have a full outer energy level, which makes them chemically inert.
The Noble Gas Core
The noble gas core is the innermost energy level of an atom, which consists of the s-orbitals and p-orbitals. The noble gas core is stable and does not readily react with other elements. The noble gas core is responsible for the chemical inertness of the noble gases.
Conclusion
In conclusion, Helium is placed in group 18 of the periodic table because of its electron configuration and the octet rule. The noble gases, including Helium, have a full outer energy level, which makes them chemically inert. The noble gas core is the innermost energy level of an atom, which consists of the s-orbitals and p-orbitals. The noble gas core is stable and does not readily react with other elements.
Aluminum and Bromine: A Chemical Reaction
Aluminum (Al) and Bromine (Br) are two elements that can undergo a chemical reaction. The reaction between Aluminum and Bromine is:
2Al (s) + 3Br₂ (l) → 2AlBr₃ (s)
In this reaction, Aluminum reacts with Bromine to form Aluminum Bromide. The reaction is exothermic, meaning it releases heat.
The Reaction Mechanism
The reaction between Aluminum and Bromine is a redox reaction, which involves the transfer of electrons. The reaction mechanism involves the following steps:
- The Aluminum atom loses three electrons to form a positive ion (Al³⁺).
- The Bromine molecule (Br₂) gains three electrons to form a negative ion (Br⁻).
- The positive ion (Al³⁺) and the negative ion (Br⁻) combine to form Aluminum Bromide (AlBr₃).
The Importance of Chemical Reactions
Chemical reactions are an essential part of chemistry, as they allow us to understand the properties and behavior of elements and their compounds. Chemical reactions are used in a wide range of applications, including the production of chemicals, fuels, and pharmaceuticals.
Conclusion
In conclusion, the modern periodic table is a powerful tool in chemistry, allowing us to predict the properties and behavior of elements and their compounds. The placement of Helium in group 18 of the periodic table is due to its electron configuration and the octet rule. The noble gases, including Helium, have a full outer energy level, which makes them chemically inert. The reaction between Aluminum and Bromine is an example of a chemical reaction, which involves the transfer of electrons. Chemical reactions are an essential part of chemistry, as they allow us to understand the properties and behavior of elements and their compounds.
References
- Atkins, P. W., & De Paula, J. (2010). Physical chemistry. Oxford University Press.
- Brown, T. E., & LeMay, H. E. (2014). Chemistry: The Central Science. Pearson Education.
- Petrucci, R. H., Harwood, W. S., & Herring, F. G. (2016). General chemistry: Principles and modern applications. Pearson Education.
The Modern Periodic Table: A Q&A Guide =============================================
Introduction
The modern periodic table is a powerful tool in chemistry, allowing us to predict the properties and behavior of elements and their compounds. In this article, we will answer some of the most frequently asked questions about the periodic table.
Q: What is the periodic table?
A: The periodic table is a tabular arrangement of the known chemical elements, organized by their atomic number (number of protons in the nucleus), electron configuration, and recurring chemical properties.
Q: Why is the periodic table arranged in a grid?
A: The periodic table is arranged in a grid because the elements in each group exhibit similar chemical properties due to the same number of electrons in their outermost energy level. The elements in each period exhibit similar chemical properties due to the same number of electron shells.
Q: What are the groups in the periodic table?
A: The groups in the periodic table are:
- Group 1: Alkali metals
- Group 2: Alkaline earth metals
- Group 13: Boron group
- Group 14: Carbon group
- Group 15: Nitrogen group
- Group 16: Chalcogens
- Group 17: Halogens
- Group 18: Noble gases
Q: What are the periods in the periodic table?
A: The periods in the periodic table are the rows of elements. Each period represents a new energy level, and the elements in each period exhibit similar chemical properties.
Q: Why is Helium placed in group 18 of the periodic table?
A: Helium is placed in group 18 of the periodic table because of its electron configuration. The electron configuration of Helium is:
1s²
This means that Helium has two electrons in its 1s orbital, which is the innermost energy level. The 1s orbital is a s-orbital, which means it is spherical in shape and can hold a maximum of two electrons.
Q: What is the octet rule?
A: The octet rule states that atoms tend to gain, lose, or share electrons to achieve a full outer energy level, which consists of eight electrons. This is known as a stable configuration.
Q: What is the noble gas core?
A: The noble gas core is the innermost energy level of an atom, which consists of the s-orbitals and p-orbitals. The noble gas core is stable and does not readily react with other elements.
Q: What is a redox reaction?
A: A redox reaction is a chemical reaction that involves the transfer of electrons. In a redox reaction, one element loses electrons to form a positive ion, while another element gains electrons to form a negative ion.
Q: What is the importance of chemical reactions?
A: Chemical reactions are an essential part of chemistry, as they allow us to understand the properties and behavior of elements and their compounds. Chemical reactions are used in a wide range of applications, including the production of chemicals, fuels, and pharmaceuticals.
Q: What is the difference between a chemical reaction and a physical change?
A: A chemical reaction is a process in which one or more substances are converted into new substances, resulting in a change in their chemical composition. A physical change, on the other hand, is a process in which a substance changes its state or properties, but its chemical composition remains the same.
Q: What is the difference between an endothermic and an exothermic reaction?
A: An endothermic reaction is a reaction that absorbs heat from the surroundings, resulting in an increase in the temperature of the surroundings. An exothermic reaction, on the other hand, is a reaction that releases heat to the surroundings, resulting in a decrease in the temperature of the surroundings.
Conclusion
In conclusion, the modern periodic table is a powerful tool in chemistry, allowing us to predict the properties and behavior of elements and their compounds. The periodic table is arranged in a grid, with the elements in each group exhibiting similar chemical properties due to the same number of electrons in their outermost energy level. The noble gases, including Helium, have a full outer energy level, which makes them chemically inert. Chemical reactions are an essential part of chemistry, as they allow us to understand the properties and behavior of elements and their compounds.
References
- Atkins, P. W., & De Paula, J. (2010). Physical chemistry. Oxford University Press.
- Brown, T. E., & LeMay, H. E. (2014). Chemistry: The Central Science. Pearson Education.
- Petrucci, R. H., Harwood, W. S., & Herring, F. G. (2016). General chemistry: Principles and modern applications. Pearson Education.