As scientists have learned more about atoms, models of atoms have changed. One of the first atomic models was a solid ball, such as a marble. What are two limitations of using a marble to model an atom?

A. the model does not move or behave like a real atom.

B. the model is not made of commonly available materials or objects.

C. the model does not show the true size of an atom.

D. the model is much harder to see than a real atom.

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

Determine the percent sulfuric acid by mass of a 1.61 m aqueous solution of h2so4. %

Atrain travels 74 kilometers in 3 hours, and then 81 kilometers in 5 hours. what is its average speed?