Which reaction would occur at the anode in a voltaic cell? Mg(s)→Mg2++2e−

Cd2+(aq)+Zn(s)→Zn2+(aq)+Cd(s)

K+(aq)+e−→K(s)

Cu2(aq)+2e−→Cu(s)

Which supports the idea that birds and butterflies both have wings but they do not have a common ancestor with wings? a. the wings are analogous structures that evolved differently and do not have a similar internal structure. b. the wings are homologous structures that evolved differently and do not have a similar internal structure. c. wings of birds are vestigial structures, but the wing structures of bats are not vestigial. d. wings of bats are vestigial structures, but the wing structures of birds are not vestigial

The solubility of barium nitrate is 9.02 g/100 g h2o at 20°c. a 15.2 g sample of barium nitrate is added to 200.0 g of water at 20°c. is the solution saturated, unsaturated, or supersaturated? a. unsaturated b. saturated c. supersaturated

Concentrations expressed as a percent by mass are useful when the solute is a a. liquid b. gas c. solid