Chemistry: Dalton's Atomic Theory & Changes

What did Dalton propose about atoms in his atomic theory?

Which model did Thomson propose regarding the structure of the atom?

What significant discovery did Rutherford make regarding the atom?

According to Bohr's model, how do electrons behave around the nucleus?

What did the quantum mechanics introduced by Schrödinger and others describe about electrons?

Dalton's Atomic Theory

Proposed by John Dalton in 1807
Atoms are the smallest unit of an element
Atoms are indivisible and cannot be broken down further
Atoms of the same element are identical in mass and properties
Atoms of different element have different masses and properties
Atoms combine in simple whole-number ratios to form compounds

Later Changes to Dalton's Theory

1897: J.J. Thomson discovered the electron, leading to the "plum-pudding" model, where electrons are embedded in a positively charged sphere
1909: Ernest Rutherford conducted the gold foil experiment, leading to the discovery of the nucleus and the "planetary model," where electrons orbit a dense, positively charged nucleus
1913: Niels Bohr proposed the "Bohr Model," where electrons orbit the nucleus in specific energy levels or shells
1932: James Chadwick discovered the neutron, a neutral particle found in the nucleus alongside protons
1926 onwards: Development of quantum mechanics by Erwin Schrödinger, Max Born, and Werner Heisenberg, which describes the likelihood of finding an electron in a particular region of space, known as atomic orbitals

Explore the foundations of Dalton's Atomic Theory as proposed by John Dalton in 1807 and the subsequent modifications introduced by scientists like J.J. Thomson, Ernest Rutherford, and Niels Bohr. This quiz covers key concepts including the nature of atoms, their combination, and advancements in atomic models over time.