11. Who was the scientist who first explained the concept of inertia?
A. Galileo Galilei B. Sir Isaac Newton C. Nicolas Copernicus D. Aristotle When a ball rolls on the floor, it will eventually stop.

12. What force causes the ball to stop?
A. weight B. inertia C. gravity D. friction

13. Which of the following is Galileo’s assertion on horizontal motion?
A. No force is needed to start the motion of an object.
B. No force is required to decrease or increase the motion of an object. C. When an object is left alone, it will continue to move with constant velocity. D. The inertia of an object will keep the object moving with constant velocity.

14. In Galileo’s experiment, what force, aside from friction, affects the motion of the ball in rolling up and down the inclined planes?
A. gravity B. weight C. friction D. inertia

15. Who among the following theorized that a particle can also exhibit wave characteristics?
A. Clinton Davisson B. Lester Germer C. Louis de Broglie D. Albert Einstein


16. What part of the de Broglie wavelength shows the particle nature of a photon?
A. p or momentum B. λ or wavelength C. h or Planck’s constant D. c or speed of light

17. Which property of a wave was observed in the behavior of electrons in Davisson and Germer’s experiment using recrystallized nickel?
A. interference B. diffraction C. polarization D. reflection

18. Which of the following statements is true about atomic spectra?
A. It is an energy given to the electron. B. It is a series of colored lines with black spaces in between.
C. It is also called photons.
D. It is discrete bundle of electromagnetic energy moving at the speed of light.

19. How is frequency related to the energy an electron carries?
A. increasing the frequency would increase the energy of the ejected electrons
B. increasing the frequency would decrease the energy of the ejected electrons 22
C. increasing the frequency would not change the energy of the ejected electrons
D. increasing the frequency would split the energy of the ejected electrons

20. Given the following electromagnetic waves, which order shows an increasing amount of energy carried by the waves? A. Visible light, microwave, gamma ray
B. Infrared, visible light, ultraviolet
C. X-ray, gamma ray, radio wave
D. Gamma ray, x-ray, ultraviolet
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