Identify the mineral in the table that is hard, has a black streak, and has no reaction with acid.

Which feature do highland climates have that lower elevation areas do not?

Which statement best describes the relationship between period and frequency of light waves? a) in wave b the period increases and the frequency decreases from wave a. b) in wave a the period increases and the frequency decreases from wave b. c) in wave b the period is shorter and the frequency is greater than in wave a. d) in wave a the period is shorter and the frequency is greater than in wave b.

Ineed to find the answer of this question because i dont understand it