Question

history of the atom
chemistry
name:
match the scientist to their discovery/discoveries: each of these scientists contributed to our current understanding of the atom.
james chadwick
j j thomson
john dalton
ernest rutherford
niels bohr
the nucleus also contains neutrons.
the nucleus contains particles called protons.
electrons orbit the nucleus in fixed shells.
atoms have a positive nucleus.
atoms contain negative particles called electrons.
elements are made from solid spheres.
describe j j thomson’s plum pudding model of an atom and explain what would happen if alpha particles were fired at atoms (according to the model).
main stage
launch
from the greek word “atomos” meaning indivisible

Explanation:

1. James Chadwick: Discovered the neutron, adding to the understanding of atomic - nucleus composition.
2. J.J. Thomson: Proposed the plum - pudding model of the atom, suggesting that electrons were embedded in a positively - charged “pudding”.
3. John Dalton: Proposed that elements are made of solid spheres (atoms), and atoms of different elements have different properties.
4. Ernest Rutherford: Discovered that the nucleus contains particles called protons and that the nucleus is small, dense, and positively charged (gold - foil experiment). Also, he contributed to the understanding that atoms have a positive nucleus.
5. Niels Bohr: Proposed that electrons orbit the nucleus in fixed shells.

If alpha particles were fired at atoms according to J.J. Thomson's plum - pudding model, the alpha particles would mostly pass straight through the atom because the positive charge and mass were thought to be evenly distributed, with no concentrated, dense nucleus to deflect the alpha particles significantly.

Answer:

1. James Chadwick - The nucleus also contains neutrons.
2. J.J. Thomson - Atoms contain negative particles called electrons.
3. John Dalton - Elements are made from solid spheres.
4. Ernest Rutherford - The nucleus contains particles called protons; Atoms have a positive nucleus.
5. Niels Bohr - Electrons orbit the nucleus in fixed shells.

If alpha particles were fired at atoms according to J.J. Thomson's plum - pudding model, most alpha particles would pass straight through with little to no deflection.