Which does not show earths past environment?

Please hurry I need this :((

Electrons are extremely important to what area of technology? a) anti-aging research b) household product development c) electronics d) drug discovery

16. why must the number of electrons lost equal the number of electrons gained in every redox reaction? use 3 – 4 sentences in your own words to address this question. 18. what type of radiation is emitted when chromium-51 decays into manganese-51? show the nuclear equation that leads you to this answer. 19. a radioactive nucleus alpha decays to yield a sodium-24 nucleus in 14.8 hours. what was the identity of the original nucleus? show the nuclear equation that leads you to this answer.

Calculate the frequency of a wave in a spring toy. the wave has a speed of 1.1 meters per second and a wavelength of 0.1 meters. *