Atomic Theory Timeline

Which scientist saw the atom as a positively charged sphere with negative particles (electrons) embedded within?

• J.J. Thomson
• Niels Bohr
• John Dalton
• Ernest Rutherford

Tags

NGSS.MS-PS1-1

Which scientist proposed a model of the atom in which the electrons are orbiting at different levels?

• Niels Bohr
• James Chadwick
• John Dalton
• Ernest Rutherford

Bohr's model of the atom proposed that ___.

• electrons move around the nucleus in fixed orbits
• neutrons move around the nucleus
• neutrons do not exist, but are just paired protons and electrons
• the nucleus spins

J.J. Thomson's model of the atom is given this name because he believed that electrons were spread randomly throughout a positive sphere.

• plum pudding model
• orbital model
• Thomson's model
• plasma model

Which scientist used his gold foil experiment to show that an atom has a small, central, positively charged nucleus that contains most of the atom's mass?

• Rutherford
• Bohr
• Thomson
• Dalton

Tags

NGSS.HS-PS1-8

Which scientist discovered that most of an atom's mass is contained in its nucleus and the rest is nearly empty space?

• Rutherford
• Dalton
• Bohr
• Thomson

Tags

NGSS.HS-PS1-8

Order the atomic models below from the oldest to the mot recent.

• 2, 1, 3, and 4
• 1, 2, 4, and 3
• 3, 2, 4, and 1
• 3, 1, 2, and 4

Tags

NGSS.MS-PS1-1

Which scientist proposed a model of the atom in which the individual atoms were thought of as tiny solids like balls or marbles?

• John Dalton
• James Chadwick
• Ernest Rutherford
• J.J. Thomson

One of the Dalton's conclusions concerning his atomic theory was that all the atoms of the same element are ___.

• the same
• different
• combined
• reacted

Which statement is true according to current thinking?

• An atom is mostly empty space.
• An atom is a collection of particles, so tightly packed that there is little empty space.
• The atomic nucleus is very mobile, and moves around inside a cloud of electrons.
• The size of atoms changes over time, pulsating from large to small to large again.