2. periods are that run from left to right 3. elements in the same period have the same every element in the first period has element in the second period has pattern? shell for its for its every see the 5. groups are that run from top to bottom. 6. the elements of a group have the same number of shell. in their 7. every element in group one has element in group two has electron in its outer shell. every electrons in its outer shell. 8. hydrogen is special because it can act like two groups, and 9. hydrogen sometimes is electron. an electron and sometimes it has an electrons in its outer shell, it is grouped 10. although helium has only with elements that have elements. they each 11. the green elements on this table are called have two electrons in their outer shell.
What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 480 ? the index of refraction of the film is 1.34, and there is air on both sides of the film. express your answer in nanometers. hint 1. how to approach th
Suppose a force of 60 n is required to stretch and hold a spring 0.1 m from its equilibrium position. a. assuming the spring obeys hooke's law, find the spring constant k. b. how much work is required to compress the spring 0.5 m from its equilibrium position? c. how much work is required to stretch the spring 0.6 m from its equilibrium position? d. how much additional work is required to stretch the spring 0.1 m if it has already been stretched 0.1 m from its equilibrium? a. kequals 600