Question

State the main postulates of Dalton's atomic theory. Explain how the modern atomic theory contradicted Dalton's atomic theory.

Answer 1

Understanding the concept:

• According to dalton's atomic theory Atoms are indivisible in nature.
• According to modern atomic theory, Atoms are divisible in nature and made up of protons, electrons, and neutrons.

Explanation of Daltons and modern atomic theory:

Daltons Atomic theory:

In a chemical reaction, atoms are indestructible particles that cannot be formed or destroyed.

• The masses and chemical characteristics of atoms of various elements differ.
• Compounds are formed when atoms join in modest whole number ratios.
• The mass and chemical characteristics of atoms of the same element are equal.
• The masses and chemical characteristics of atoms of various elements differ.
• A compound's relative quantity and types of atoms remain constant.
• Modern atomic model: The modern model is the most advanced and commonly accepted atomic model today.
• This model is also called the electron cloud model.
• It keeps the nucleus concept from Bohr & Rutherford's models but offers a new definition for electron velocity around the nucleus.

The contradiction of modern atomic theory with daltons atomic theory:

• Atoms are divided into protons, neutrons, and electrons, according to modern atomic theory, which contradicts Dalton's atomic theory.
• Isotopes are atoms of the same element that exhibit distinct properties.
• Isobars are atoms that have the same characteristics in different elements.