Answer:hydrogen atomic no and mass no is 1. In hydrogen there is one electron ,one proton and zero neutron.
Explanation:
Neutron is zero because neutron
Nnumber =atomic no - mass no so 1-1=0.
Come from a common ancestor
B. Second level consumer because it is not a plant(producer). It is not a decomposed and it is eating the mouse , a first level consumer .
The theory that a drug attaches itself to specialized cells in the body because of its size, shape, electrical charge, and chemical properties is called receptor site theory.
c.