Modern Periodic Table | Chemistry Class 10 #3

TL;DR

The modern periodic table organizes elements based on their atomic number, overcoming limitations of the previous periodic table.

Transcript

hello friends I am back and today we are going to learn about the modern periodic table in 1913 Henry Moseley showed that atomic number is a more fundamental property than atomic mass and therefore he gave the modern periodic law so modern periodic law stated that the periodic properties of elements are a periodic function of their atomic numbers a... Read More

Key Insights

• 🫀 The modern periodic table organizes elements based on their atomic numbers, which proved to be a more fundamental property than atomic mass.
• 🚰 The modern periodic table resolves the position of isotopes, cobalt and nickel, and hydrogen that were limitations of the previous periodic table.
• #️⃣ Elements with decimal atomic numbers between whole numbers are ruled out in the modern periodic table.
• #️⃣ Periods in the modern periodic table have consecutive atomic numbers and a fixed number of elements based on the maximum number of electrons in various electron shells.
• 👥 Groups in the modern periodic table have similar electronic configurations and physical and chemical properties due to the same number of valence electrons.
• 👥 The period and group of an element can be determined by its electronic configuration, with the period determined by the outermost shell and the group determined by the number of valence electrons.
• 🚫 S block, p block, and d block elements are classified based on the orbital where the last electron enters - s, p, and d orbitals respectively.

Questions & Answers

Q: What is the basis of the modern periodic table?

The modern periodic table is based on the concept that the properties of elements are a periodic function of their atomic numbers.

Q: How does the modern periodic table handle the position of isotopes?

The modern periodic table places isotopes in the same position since they have the same atomic number, unlike the previous periodic table based on atomic mass.

Q: How does the modern periodic table resolve the position of cobalt and nickel?

The modern periodic table places cobalt after nickel because cobalt has an atomic number of 27 and nickel has an atomic number of 28, providing a clear sequence based on atomic number.

Q: What determines the position of hydrogen in the modern periodic table?

Hydrogen is placed in Group 1 and Period 1 of the modern periodic table due to its atomic number of 1 and one valence electron.

Summary & Key Takeaways

• Henry Moseley introduced the modern periodic law, which states that the periodic properties of elements are a function of their atomic numbers rather than atomic masses.

• The modern periodic table overcame limitations such as the position of isotopes, the position of cobalt and nickel, and the position of hydrogen.

• The modern periodic table does not allow for elements with decimal atomic numbers between whole numbers, resolving the possibility of new elements in between existing ones.