A compound of hydrogen carbon and oxygen contains 71.12g of oxygen and 2.2 g of hydrogen the rest is carbon. it has a relative molecular mass of 90 find its emperical formula

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.

What does a complete balanced chemical equation include? a. exothermic coefficients b. endothermic coefficients c. valence electrons d. molar coefficients

Which of the following is not an assumption that scientists must make about the natural world? a. regularity b. causality c. predictability d. plausibility