Is it general principal that more abundant isotopes exist in 1. even atomic no.
2. odd atomic no.
3. even mass no.
4. odd mass no.

Which statement describes evidence of a chemical reaction? a) ice melting eliminate b) water boiling c) lighting a match d) grape juice freezing

What type of reaction is shown below? check all that apply. 2h2o2 → 2h2o + o2 synthesis decomposition combustion

Aradio signal from a gps satellite take only about 0.067 seconds to reach a gps reciever. if the speed of light is about 300,000km/s, then approximately how far away is the reciever from from the satellite?