12. Which of the following species would require the highest energy for the removal of one electron? A. Na* B. Ne C. F D. Mg²+ 13. How many 3d electrons are present in the ground state of chromium atom? A. 9 B. 6 C. 4 D.5 B. 3 C. 4 D. 1 14. How many significant digits in 0.0250g? A. 2 15. Which orbital cannot exist A. 2p B. 4D C. 2d 16. which one is permissible set of quantum number? A. n-3 1-3 ml= -3 B. n-3 1-1 ml=+2 C. n=0 1=0 ml = 0 D. n-3 1-2 ml= -2 17. Calculate the wave length of an electron that has a velocity of 100x10°m/s (me-9. h= 6.626x10-341/s). A. 6.17x10 m B. 7.27x10 m C. 5.97x10 m D. 2.19x1
