Atomic History No Women so no Herstory just History Flashcards
Remember the fucken history!
Who was John Dalton, and what was his contribution to atomic theory?
John Dalton was a scientist who proposed the atomic theory in 1808. He described atoms as small, hard, indivisible spheres that make up matter.
What were the key points of Dalton’s atomic theory?
All matter is made of tiny, indivisible particles called atoms.
Atoms of the same element are identical, while atoms of different elements are different.
Atoms combine in simple whole-number ratios to form compounds.
Chemical reactions involve the rearrangement of atoms but do not create or destroy the
What experiment did J.J. Thomson conduct, and what did he discover?
J.J. Thomson used cathode ray tubes to study electric currents in gases and discovered the electron in 1897.
What was the “plum pudding model” of the atom?
Thomson’s model depicted the atom as a positively charged sphere with negatively charged electrons embedded in it, like plums in pudding.
What experiment did Rutherford conduct, and what were the results?
Rutherford performed the gold foil experiment, where he shot alpha particles at a thin gold foil. Most particles passed through, but some were deflected, indicating a dense, positively charged nucleus.
How did Rutherford’s model of the atom differ from Thomson’s?
Instead of a uniform sphere, Rutherford proposed that the atom has a dense, positively charged nucleus with electrons orbiting around it.
What was Bohr’s contribution to atomic theory?
Bohr proposed that electrons exist in fixed energy levels (orbits) around the nucleus and can jump between these levels by absorbing or emitting energy.
How did Bohr’s model explain atomic spectra?
Bohr’s model explained that atoms emit specific wavelengths of light when electrons transition between energy levels, producing line spectra.
What problem did Rutherford’s model have?
It couldn’t explain why electrons didn’t spiral into the nucleus due to energy loss.
What discovery did James Chadwick make?
In 1932, Chadwick discovered the neutron, explaining the missing atomic mass that Rutherford’s model couldn’t account for.
