Vai trò của ngành thân mềm là gì

Resistance than a bicycle? i'm not entirely sure

The proton has a positive charge while the neutron has no charge they both make up the nucleus of the atom while the elections have a negative charge and surround the nucleus of the atom. the protons and electrons are used to calculate the atom's mass whereas the neutrons don't affect the mass

If you get a map and put the countries a states all together it forms all one piece you can also tell because of the earth quakes