Why shells are represented by KLMN?

Related questions

1. What is in bash scripting?
2. Is bash and sh the same?
3. Is Mac terminal Unix?
4. Does Mac use bash?
5. Is zsh a Posix?
6. What is TCSH command?
7. What does C mean in bash?
8. What is bin sh Linux?
9. Is Mac same as Linux?
10. What is the difference between TCSH and bash?

Tags

1. #energy
2. #charles
3. #label
4. #electron
5. #called
6. #named
7. #emitted
8. #atoms
9. #studied
10. #shells
11. #shell
12. #spectroscopist
13. #electrons
14. #names
15. #innermost
16. #fellow
17. #barkla
18. #after