I will mark brainlist please help

1) Which of these is not a characteristic of a wave?

A. amplitude

B. period

C. mass

D. velocity


2) if a wavelength is denoted as ‘ʎ’ then the shortest horizontal distance between a crest and a trough is equal to:


A. 3/2 ʎ

B. ʎ

C. 2 ʎ

D. 1/2 ʎ