1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Four Fundamental Forces in Nature Force – a _____ or _____ SI unit of force – ______ Four Forces in Nature: Chapter 18 1. Gravitational 2. Electromagnetic 3. Weak Nuclear 4. Strong Nuclear

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Four Fundamental Forces in Nature 1.Gravitational Force ________ force between all objects Acts over a very ____ distance ________ force (6 x 10 -39 ) Examples: Chapter 18 two small objects earth and person moon and person earth and moon

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Four Fundamental Forces in Nature 2. Electromagnetic Force Charged particles exert an _______ force Acts over a very ____ distance ______ force (7 x 10 -3 ) Force can be ________ (+ & -) or _______ (+ & + or - & -) This force holds the _______ in the atom Chapter 18

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Four Fundamental Forces in Nature 3. Weak Nuclear Force _______ force (10 -6 ) Acts over the _______ distance – within the neutron (10 -18 m) ________ force Involved in _________ decay – beta decay Chapter 18

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Four Fundamental Forces in Nature 3. Weak Nuclear Force Involved in radioactive decay – beta decay causes a _______ to break down ejecting a ____ particle (electron which comes from the nucleus) causes _______to change into a _______ 1 n 1 p + 0 e 0 +1 -1 Chapter 18 1 n 1 p + 0 0 +1 -1

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Four Fundamental Forces in Nature 4. Strong Nuclear Force Why do positively charged protons not repel each other and fly out of the nucleus? This force holds _______and _______ together in the nucleus __________ force __________ force (1) Acts over very _____ distance (10 -15 m) Chapter 18