The purpose of an experiment is often based on

Solar energy is energy from the sun that is converted into thermal or energy. a. nuclear b. mechanical c. electrical d. chemical

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

Which element has the lowest electronegativity? calcium(ca) gallium(ga) selenium(se) bromine(br)