Answer:
Fluorine is the most reactive element
Infra-red has wavelengths just longer than visible light.
Answer:
In a standing sound wave in a pipe, nodes are regions of mean atmosphere pressure and low displacement.
Answer:
(a) Waves P and Q have the same wavelength but wave P has twice the amplitude of wave Q.
(b) Waves Q and R have the same amplitude but wave R has twice the wavelength of wave Q.
(c) Wave T shows a steady frequency but changing amplitude.
(d) Wave S shows steady amplitude but a changing frequency.
e) Waves Q and R have a low amplitude and a steady frequency.
