The development of the model of the atom

What can new evidence cause scientists to do?

• Ignore it
• Change their ideas
• Destroy old models
• Create new atoms

Before the electron was discovered, what did people think atoms were?

• Tiny spheres that couldn't be divided
• Large balls of energy
• Particles with a nucleus
• Balls of negative charge

What model came from the discovery of the electron?

• Nuclear model
• Solar model
• Plum pudding model
• Planetary model

What did the plum pudding model suggest about atoms?

• Atoms have a nucleus
• Atoms are empty space
• Atoms are balls of positive charge with negative electrons inside
• Atoms are solid positive charges

What did the alpha particle scattering experiment show about the atom? select 2

• It is mostly empty space
• The mass is concentrated at the centre (nucleus)
• Atoms are indivisible
• Electrons are at the centre

Which model replaced the plum pudding model after the alpha particle scattering experiment?

• Planetary model
• Alpha model
• Electron cloud model
• Nuclear model

What did Niels Bohr suggest about electrons?

• Electrons are stationary
• Electrons orbit the nucleus at specific distances
• Electrons are inside the nucleus
• Electrons are positively charged

What did later experiments show about the nucleus’s positive charge?

• It can be negative
• It is indivisible
• It comes from smaller particles called protons
• It is made of electrons

Who provided evidence for neutrons in the nucleus?

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

How many years after the nucleus was accepted was the neutron discovered?

• 10 years
• 20 years
• 30 years
• 40 years