It's known as the greenhouse effect.
The unit of momentum is the product of the units of mass and velocity.
Answer:
The immune system responds to antigens by producing cells that directly attack the pathogen, or by producing special proteins called antibodies. Antibodies attach to an antigen and attract cells that will engulf and destroy the pathogen. The main cells of the immune system are lymphocytes known as B cells and T cells.
NH4+ and NH3 are an acid-conjugate base pair, since NH4+ is an acid, while NH3 is its conjugate base (since it is without the H+).
H2O and H3O+ can also be considered an acid-conjugate base pair, since H3O+ is an acid, while H2O would be its conjugate base. (But if only 1 answer is to be selected, it should be the NH4+ and NH3)
NH4+ and H3O+ are both acids, and both H2O and NH3 can be considered bases.
8 because atomic number is the same as number of protons, protons and electrons have the same amount so that the element is neither positive nor negative.