I think the answer is
Made up of three consecutive verbs, two in the past tense
Can + did + ate (the second and third are in the past tense).
Starts with a noun and ends with a noun
Starts with can and ends with date
Starts with a metal, ends with kind of metal
Ca is the chemical symbol for calcium, a metal
Te is the chemical symbol for Tellurium, a metalloid.
Starts with a number, ends with a number
C is the Roman numeral for 100
ate sounds like eight (or possible e, as suggested by JonMark Perry)
Competitor is synonymous with candidate