Which of the following statements best describes the layer of Earth just beneath the outermost layer?
A. a cold, brittle lithosphere
B. a hot, convecting mantle
C. a dense, metallic core
D. a dense, metallic liquid

11. phosphorus-32 is radioactive and has a half life of 14 days. how much of a 124 mg sample of phosphorus-32 is present after 56 days? a) 7.75 mg b) 15.5 mg c) 31.0 mg d) 62.0 mg

Which best describes the activation energy of a chemical reaction? a. the combined energy of all the reactants b. the amount of energy required for a reaction to occur c. the difference in energy between products and reactants d. the potential energy stored in the bonds of reactants and products

What are the two basic types of satellites