Simple Nature - Light and Matter

tinguished the different types from each other? Was it their sizes, their shapes, their weights, or some other quality? The chas ...

mHe mH = 3.97 mNe mH = 20.01 mSc mH = 44.60 d/Examples of masses of atoms compared to that of hydro- gen. Note how some, but not ...

ratios of the different atoms’ masses fairly accurately. A typical technique would be to measure how many grams of sodium (Na) w ...

the muddle. The row-and-column scheme he came up with is essen- tially our modern periodic table. The columns of the modern vers ...

f/A young Robert Mil- likan.(Contemporary) g/A simplified diagram of Millikan’s apparatus. tion for Brown’s observation: the wat ...

q /(1.64 q(C) × 10 −^19 C) −1.970× 10 −^18 −12.02 −0.987× 10 −^18 −6.02 −2.773× 10 −^18 −16.93 h/A few samples of Millikan’s dat ...

The table on the left shows a few of the results from Millikan’s 1911 paper. (Millikan took data on both negatively and positive ...

i/Cathode rays observed in a vacuum tube. rectly evaluate the implications of the fact that scientific fraud has sometimes exist ...

j/J.J. Thomson in the lab. Were cathode rays a form of light, or of matter? Were cathode rays a form of light, or matter? At fir ...

that they were indeed electrically charged, which was strong evi- dence that they were material. Not only that, but he proved th ...

Thomson played with the electric and magnetic forces until ei- ther one would produce an equal effect on the beam, allowing him ...

l/The raisin cookie model of the atom with four units of charge, which we now know to be beryllium. C Thomson found that them/qo ...

a four-electron atom. All four electrons would be repelling each other, but they would also all be attracted toward the center o ...

the object with a net positive charge, which attracts the lost sheep home to the fold. (For objects immersed in air rather than ...

a/Henri Becquerel (1852-1908). b/Becquerel’s photographic plate. In the exposure at the bottom of the image, he has found that h ...

thickness of material the radioactivity could get through. They soon learned that a certain fraction of the radioactivity’s inte ...

c/A simplified version of Ruther- ford’s 1908 experiment, showing that alpha particles were doubly ionized helium atoms. d/These ...

e/Ernest Rutherford (1871- 1937). f/Marsden and Rutherford’s apparatus. It was already known that although alpha particles would ...

h/The planetary model of the atom. g/Alpha particles being scattered by a gold nucleus. On this scale, the gold atom is the size ...

particle. It turned out that it was not even too difficult to derive a formula giving the relative frequency of deflections thro ...