Lithium has a work function of 2.3ev. If 400nm light is incident on it, what is the maximum kinetic energy ? Chemistry Bohr Model of the Atom Calculations with wavelength and frequency
No. A comma precedes such as when what follows is an example of whatever went before. In this case, it is nonrestrictive. (For nonrestrictive constructions: use a comma.).
I only use one space after colon and semi-colon. They are intermediate place punctuation, unlike full stop, exclamation and query which are terminators. One space either side of a dash - but none when the - is a hyphen. When I was working on Apple Macs, I used a long dash for dash and a short dash for hyphen.