Why do capillaries need to be thin walled?
a so only a few nutrients can pass through
b so only a small amount of blood can flow through
c so they can go through the small spaces within the body
d so the exchange of gases and nutrients can happen

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

Ithink b hope that