Science 8 Performance Task (2nd Quarter)

Who proposed that all matter is made up of tiny, indivisible particles called atoms?

• Aristotle
• Democritus
• Dalton
• Thomson

What was John Dalton’s major contribution to the atomic theory?

• Atoms have a nucleus
• Atoms are mostly empty space
• Atoms of each element are identical
• Atoms contain neutrons

Which scientist discovered the electron?

• Ernest Rutherford
• J.J. Thomson
• Niels Bohr
• James Chadwick

What experiment led to the discovery of the nucleus?

• Cathode Ray Tube Experiment
• Oil Drop Experiment
• Gold Foil Experiment
• Atomic Bomb Experiment

According to Rutherford’s model, where is the positive charge concentrated?

• Evenly spread throughout atom
• In the nucleus
• In the electron cloud
• In the orbitals

Who proposed that electrons move around the nucleus in fixed paths or energy levels?

• Dalton
• Bohr
• Thomson
• Rutherford

Which subatomic particle was discovered last?

• Electron
• Proton
• Neutron
• Nucleus

What is the main idea of Bohr’s atomic model?

• Electrons orbit nucleus in fixed energy levels
• Atoms are indivisible
• The atom is mostly empty space
• Atoms combine in whole number ratios

What did Chadwick’s discovery of the neutron help explain?

• The atom’s chemical behavior
• The atom’s mass and stability
• The electron’s charge
• The energy levels in atoms

Which modern atomic model describes electrons as moving in a cloud rather than fixed orbits?

• Bohr Model
• Quantum Mechanical Model
• Rutherford Model
• Thomson Model