Great work with this assignment.
Let’s start by looking at your second and third photograph.
Your second photograph (side profile) contains many of the tonal qualities you’ll be looking for in a black and white photograph. It’s relatively balanced in its tonal representation in black and whites which means it’s neither low key nor high key. However, that’s not necessarily wrong, it’s all a matter of preference.
Your first image uses a predominance of light tones which gives it a slightly unbalanced tonal quality which is great.
My only concern with this assignment is your last image. While it’s one of my favourite compositions out of the three photographs, it doesn’t make the strongest black and white photograph. There are too many grey tones in the photograph and it’s completely void of any white tones which means it lacks range.
I’ve uploaded the tonal spectrum for your second image (profile) and your third image (hands) so you can see how in your third photo (hands) you virtually have no representation of white at all.
My second concern is that your images are fairly noisy. I sense you are using too high an ISO speed. Generally speaking the higher the ISO the grainier your images will be. Try using the lowest ISO possible under your lighting conditions to avoid this problem. I particularly notice the issue in your third image.
Overall, great work. This is what we were hoping you’d accomplish in this assignment!