Kim took 5 hours to complete a journey with an average speed of 80 km/h. For the first 3 hours, she travelled at an average
speed of 60 km/h. What was her average speed for the
remaining time of the journey?
km

Match the atomic particles with their characteristics. 1. made of two protons and two neutrons neutron 2. similar to an electron; positive charge neutrino 3. orbits nucleus; negative charge positron 4. bundle of energy; zero charge proton 5. found in nucleus; positive charge meson 6. very unstable; +, -, or zero charge gamma 7. found in nucleus; zero charge electron 8. negative particle; negative charge beta 9. atomic energy converted to mass alpha

It is really hard for me right know

What is a subatomic particle with a negative charge and very little mass?