What is the purpose of adding oil to a
car's engine?
a to increase the mass of the engine so
it can pull larger loads
b to increase the temperature and
pressure of the engine
c to reduce friction and allow the
engine to run more smoothly
d to protect the engine from insect
damage

Which of the following observations indicates that an atom has neutrons? some uncharged particles are scattered by a beryllium atom when it hits a gold foil. some uncharged particles bounce back from a gold foil when it is bombarded with alpha particles. a radiation consisting of uncharged particles is emitted when alpha particles strike beryllium atoms. a radiation which attracts electrons is produced when a beryllium atom is bombarded with alpha particles.