A particle having almost zero mass and exactly zero charge is

Step-by-step solution

We know that the neutrino is the particle which has almost zero mass and exactly zero charge. Positron has the charge +e and mass m_ e [equal to electron mass]. Electron is a particle which has -e charge and 9.1 10⁻³¹ kg mass. Neutron is a particle which has zero charge and 1838 ~m _ e mass. So, the required answer is neutrino.