What part of an original isotope’s number of atoms remains after two half lives?

In which direction will the following reaction go if the standard reduction potentials are 0.80 v for ag/ag+ and –0.44 v for fe/fe2+? ag+ + fe → ag + fe2+ a.)forward b.)the reaction cannot occur. c.) not enough information is given. d.) reverse

Water is important for the of cells. a: size, shape, and temperature b: temperature, color, and odor c: color, odor, and size d: shape, temperature, and color

What is the common name for the compound shown here? enter the common name of the compound shown?