In a lab analyzing evidence.
1 you run out of fuel 2 it takes a long time 3 it’s hard to get back 4 the conditions are constantly changing making it harder to predict what could happen. Look at Apollo 12 as a example
Protons and Neutrons affect the mass. Protons and Electrons change the charge of the atom (positively or negatively charged). Valence electrons are the ones that do fun stuff in chemical reactions, they are responsible for making/breaking bonds, at least to my understanding.
Hope this helps.
Yes. At the top of the hill they have potential energy. while riding down the hill the bike will pick up speed.
No u dont because earth gravitational pull is stronger also it is a scientific law