How does an atom become an ion with a -2 charge?

The diagram shows the structures of horse and cat forelimbs. what does the diagram suggest about the evolutionary relationship between these two mammals? a. they have homologous structures, indicating a common ancestor. b. they have analogous structures, indicating a common ancestor. c. they have homologous structures, indicating that they do not have a common ancestor. d. they have analogous structures, indicating that they do not have a common ancestor.

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?

Which statement describes the phase change that occurs when dry ice is placed in an open container at room temperature?