Question

What is the basic difference between Mendeleeff's periodic table and modern periodic table?

Short answer

Short Answer: The primary difference between Mendeleev's periodic table and the modern periodic table is their organizing principle. Mendeleev's table arranged elements based on atomic masses, while the modern periodic table arranges them based on atomic numbers. The modern periodic table is considered more accurate because it reflects the elements' electronic configurations, leading to a better understanding of their periodic properties, reactivity, and trends within groups and periods. Additionally, it is more effective at predicting properties of newly discovered elements.

Step-by-step solution

Understand Mendeleev's Periodic Table

Mendeleev's periodic table was developed by Dmitri Mendeleev in 1869. In this table, elements were arranged in increasing order of their atomic masses. Mendeleev organized the elements in a way that elements with similar properties were placed in the same group (column), thereby highlighting the periodicity of the elements' properties.

Understand the Modern Periodic Table

The modern periodic table is based on the work of many scientists, but it is primarily attributed to Henry Moseley's work in 1913. In the modern periodic table, elements are arranged in increasing order of their atomic numbers (number of protons in the nucleus). The atomic number provides a clearer and more reliable method of organizing elements, as it results in the arrangement of elements based on their electronic configurations.

Identifying the Basic Difference

The primary difference between Mendeleev's and the modern periodic table is the organizing principle. In Mendeleev's table, elements were arranged based on their atomic masses, while in the modern periodic table, elements are organized by their atomic numbers. This difference means that each element's position in the modern periodic table reflects its electronic configuration, leading to a more accurate representation of the periodic properties of elements.

Importance of the Modern Periodic Table

The modern periodic table is more accurate than Mendeleev's periodic table because it is based on atomic numbers. This organization results in a better understanding of the chemical properties of elements, their reactivity, and trends within groups and periods. The modern periodic table is also better at predicting the properties of newly discovered elements or elements not yet discovered during Mendeleev's time.