2a10.20a.jpg
2a10.20b.jpg

 

Code Number: 2A10.20

Demo Title: Surface Tension - Floating Metals

Condition: Excellent

Principle: Surface Tension

Area of Study: Fluids

Equipment:

Evaporating dish, Toothpicks, dishwashing soap, razor-blade, paperclips, needles.

Procedure:

Carefully place the metal objects in the water so that they float.  Place a drop of liquid soap on a toothpick and touch to the surface of the water.  The metal objects should sink as the surface tension is reduced or broken.

References:

  • Francisco Jose Torcal-Milla, "Can 1 kg of Iron Float on Water", TPT, Vol. 61, #8, Nov. 2023, p. 644.
  • Letters to the Editor, "Quick Way to Float a Paper Clip on Water", TPT, Vol. 46, # 2, Feb. 2008, p. 70.
  • Paul J. Dolan Jr., Charles W. Smith, "Tokar's Question: Surface Tension vs Buoyancy, TPT, Vol. 39, #2, Feb. 2001, p. 69.
  • Wojciech Dindorf, "Tokar's Question", TPT, Vol. 38, # 8, Nov. 2000, p. 488.  
  • Renate J. Ondris-Crawford and Lisa R. Hilliard, "It's All on the Surface", TPT, Vol. 35 # 1, Feb. 1997, p. 100.
  • R.D. Edge,  "A Pointed Demonstration of Surface Tension",  TPT, Vol. 29, # 6, p. 414, Sept. 1991.
  • Ernest K. Chapin, "The Strange World of Surface Film", TPT, Vol. 4, # 6, Sept. 1966, p. 271.
  • Antonin Marchand et al, "Why is Surface Tension a Force Parallel to the Interface?", AJP, Vol. 79, # 10, Oct. 2011, p. 999.
  • S. Straulino, C. M. C. Gambi, A. Righini, "Experiments on Buoyancy and Surface Tension Following Galileo Galilei", AJP, Vol. 79, # 1, p. 32, Jan. 2011.
  • J. Pellicer, V. Garcia-Morales, L. Gaunter, M. J. Hernandez, and M. Doiz, "On the Experimental Value of the Water Surface Tension Used in Some Textbooks", AJP, Vol. 70, # 7, July 2002, p. 705.
  • A. Raymond Penner, "Suspension of a Disk on a Surface of Water", AJP, Vol. 68, # 6, p. 549, June 2000.
  • E. K. Chapin, "Surface Tension and Floating Bodies", AJP, Vol. 24, #8, Nov. 1956, p. 587.
  • Ernest K. Chapin, "Surface Tension and Floating Bodies", AJP, Vol. 24, #3, Mar. 1956, p. 178.
  • John W. M. Bush, David L. Hu, "Walking on Water", Physics Today, June 2010, p. 62.
  • George M. Hopkins', "Surface Tension", Experimental Science, Volume Two, p. 229.
  • Charles Vivian, "Testing the Skin of Water", Science Experiments & Amusements For Children, p. 20.
  • Pat Murphy, Ellen Macaulay, and the staff of the Exploratorium, "Sink or Swim", Exploratopia, p. 108.
  • Martin Gardner, "Two 10-Cent Betchas", Science Tricks, p. 10.
  • Martin Gardner, "17, A Floating Coin", Smart Science Tricks, p. 30.
  • F- 330:  "Sieve Bucket - Float Needle",  DICK and RAE Physics Demo Notebook.
  • Bobby Mercer, "Mysterious Floating Paper Clip" Junk Drawer Chemistry, 2016, p. 30.
  • W. Bolton, "Wetting Agents", Book I - Properties of Materials, Physics Experiments and Projects, 1968, p. 22.
  • Herb Strongin, “Floating a Needle That No One Else Can“, Science on a Shoestring, p. 5.