Make one table with your list of 100 contacts. Make another table in the same base with a linked field to your original table. I.E. “Person” field in Table B is a link to another record field type connecting to “Full Name” or “Social Handle” field in Table A.
Make the form in Table B. When your contacts complete the form, they’ll be able to select from a list of contacts using your linked “Person” field. Now in Table A you’ll have a new column showing all responses connected to each contact. Any contact with an empty cell in that column hasn’t filled out the form.