What is the Difference Between Dalton’s Atomic Theory and Modern Atomic Theory?

Dalton's Atomic Theory and Modern Atomic Theory are two models that describe the nature of atoms. While both theories agree on some points, they differ significantly in certain aspects. Here are the main differences between the two theories:

1. Indivisibility: Dalton's Atomic Theory states that atoms are indivisible particles, whereas Modern Atomic Theory says that atoms can be divided into subatomic particles like protons, neutrons, and electrons.
2. Mass: Dalton's Atomic Theory posits that atoms of different elements differ in size and mass, whereas Modern Atomic Theory states that atoms of the same element have the same chemical properties and a characteristic average mass unique to that element.
3. Isotopes: Modern Atomic Theory acknowledges the existence of isotopes, where atoms of the same element have different atomic masses, while Dalton's Atomic Theory claims that atoms of the same element are identical in properties like shape, size, and mass.
4. Creation and Destruction: According to Dalton's Atomic Theory, atoms can neither be created nor destroyed, while Modern Atomic Theory suggests that atoms of different elements can be created using nuclear reactions.
5. Combination Ratios: Dalton's Atomic Theory states that atoms combine with each other in simple whole-number ratios to form compound atoms, while Modern Atomic Theory says that atoms may not always combine in simple ratios, as demonstrated by the example of sugar (C12H22O11).

Comparative Table: Dalton’s Atomic Theory vs Modern Atomic Theory

Here is a table highlighting the differences between Dalton's Atomic Theory and the Modern Atomic Theory:

Dalton's Atomic Theory, proposed by John Dalton in 1808, laid the foundation for understanding the atomic structure. However, the Modern Atomic Theory has refined and expanded upon Dalton's ideas, providing a more accurate and comprehensive understanding of atomic structure and properties.