Choose the reaction that illustrates δh°f for ca(no3)2.

Earth's atmosphere is unique among the planets and is able to support life because it contains a large amount of a) oxygen b) helium c) methane d) carbon dioxide

Tortoise shells and snail shells are similar in function: they protect the organism from predators. based on a comparison of the organisms in the images, what can you conclude? 1. tortoises and snails have homologous organs, and they’re evolutionarily related. 2. tortoises and snails have homologous organs, and they belong to same species. 3. tortoises and snails have analogous organs, and they belong to the same species. 4. tortoises and snails have analogous organs, and they don’t belong to the same species. 5. tortoises and snails have analogous organs, and they aren’t evolutionarily related.

The graph shows a trend in an ecosystem over time caused by increased pollution in the region. what can you conclude from the graph? a. there’s lower biodiversity among birds. b. there’s a higher reproductive rate among birds. c. there’s a significant decline in the number of producers. d. other types of animals were unaffected by pollution.