What is the change in internal energy if 30 J of thermal energy is released from a system, and the system does 40 J of work on the surroundings? Use U = Q - W. A. 70 J B. 10 J C. -10 J D. -70 J

Which type of bond is found between the atoms of a molecule? a. metallic b. delocalized electron c. covalent d. ionic

Explain the difference between each pair of concepts. a. frequency and relative frequency b. percentage and relative frequency a. select the correct choice below. a. frequency is the total number of observations in a data set. relative frequency is the number of times a particular distinct value occurs. b. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of a value to the total number of observations. c. frequency is the total number of observations in a data set. relative frequency is the ratio of the number of times a particular distinct value occurs to the frequency. d. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of two different values.

Which additional product balances the reaction h2so4 + 2naoh → na2so4 + 2h2o 2oh h2o2 h3o