CK-12 Physical Science Concepts - For Middle School

2.37. Isotopes http://www.ck12.org 2.37 Isotopes Define isotope. Describe three isotopes of hydrogen. State how isotopes are na ...

http://www.ck12.org Chapter 2. Matter http://www.youtube.com/watch?v=6w7raarHNA8 (5:23) MEDIA Click image to the left for use th ...

2.37. Isotopes http://www.ck12.org atoms with 7 neutrons have an atomic mass of 13 (6 protons + 7 neutrons = 13). These atoms ar ...

http://www.ck12.org Chapter 2. Matter Carbon-14 slowly decays over time because it is radioactive. Why does the percent of carb ...

2.38. Democritus’ Idea of the Atom http://www.ck12.org 2.38 Democritus’ Idea of the Atom Review how and when Democritus arrived ...

http://www.ck12.org Chapter 2. Matter a chunk of matter—such as a piece of cheese into smaller and smaller pieces. He thought th ...

2.38. Democritus’ Idea of the Atom http://www.ck12.org other. When they do, he surmised, they either bounce apart or stick toget ...

http://www.ck12.org Chapter 2. Matter Summary Around 400 B.C.E., the Greek philosopher Democritus introduced the idea of the at ...

2.39. Dalton’s Atomic Theory http://www.ck12.org 2.39 Dalton’s Atomic Theory Explain why Dalton reintroduced the idea of the at ...

http://www.ck12.org Chapter 2. Matter FIGURE 2.71 He investigated pressure and other properties of gases, from which he inferre ...

2.39. Dalton’s Atomic Theory http://www.ck12.org MEDIA Click image to the left for use the URL below. URL: http://www.ck12.org/f ...

http://www.ck12.org Chapter 2. Matter MEDIA Click image to the left for use the URL below. URL: http://www.ck12.org/flx/render/e ...

2.40. Thomson’s Atomic Model http://www.ck12.org 2.40 Thomson’s Atomic Model Explain how J. J. Thomson discovered the electron. ...

http://www.ck12.org Chapter 2. Matter FIGURE 2.73 What is a cathode ray? That’s what Thomson wanted to know. Is it just a ray of ...

2.40. Thomson’s Atomic Model http://www.ck12.org Q:Atoms are neutral in electric charge. How can they be neutral if they contain ...

http://www.ck12.org Chapter 2. Matter FIGURE 2.76 http://www.youtube.com/watch?v=SZSEnCydeb0 (12:30) MEDIA Click image to the le ...

2.41. Rutherford’s Atomic Model http://www.ck12.org 2.41 Rutherford’s Atomic Model Explain how Ernest Rutherford discovered the ...

http://www.ck12.org Chapter 2. Matter MEDIA Click image to the left for use the URL below. URL: http://www.ck12.org/flx/render/e ...

2.41. Rutherford’s Atomic Model http://www.ck12.org FIGURE 2.78 The Nucleus Takes Center Stage Rutherford made the same inferenc ...

http://www.ck12.org Chapter 2. Matter FIGURE 2.79 Explore More Watch this video about Rutherford’s gold foil experiment, and the ...