Which layer of the atmosphere holds the ozone layer?

The troposphere is the first layer above the surface and contains 70 to 80 per cent of the Earth's atmosphere. Weather occurs in this layer. Also Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs harmful rays from the Sun. The ozone layer is considered to be in the troposphere layer. ( the first layer) hope this helps :) .

No. an alpha particle is a pair of protons and a pair of neutrons, i.e. a helium