Which of the following statements about chemical reactions is NOT correct? A. A chemical reaction involves chemical bonds breaking and forming.
B. An energy input is required to break bonds in the reactants.
C. Energy is released when new bonds are formed in the products.
D. The energy released when new bonds form may be greater than or less than the
energy required to break bonds in the reactants.
E. New bonds formed during rearrangement can potentially cause some atoms to
disappear and turn into energy.

What is the molecular formula for a compound that is 46.16% carbon, 5.16% hydrogen, and 48.68% fluorine? the molar mass of the compound is 156.12 g/mol

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? a. the balloons both rise. the cold balloon is larger than the warm balloon. b. the balloons rise at the same rate. both balloons are the same size. c. the warm balloon expands and rises. the cold balloon shrinks and sinks. d. the cold balloon expands and rises. the warm balloon shrinks and sinks.

Which atom or ion is the largest? a. k b. k+ c. ca d. ca2+ e. li