When testing for hydrogen gas in the laboratory a glowing splint is inserted into the gas which results in a pop sound. What is associated with the formation of the pop sound? A. physical change
B. chemical change
C. exothermic reaction
D. endothermic reaction

1) how many electrons are in each energy level of the following elements? a. he b. na c. na d. ne 2) how many valence electrons are percent in the following atoms? a. s b. mg c. be d. cl 3) which of the following elements are stable as atoms? a. he b. o c. cl d. ar if you are able to provide the work as to how you got the answers that would be greatly appreciated. : )

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

Which buffer would be better able to hold a steady ph on the addition of strong acid, buffer 1 or buffer 2? explain. buffer 1: a solution containing 0.10 m nh4cl and 1 m nh3. buffer 2: a solution containing 1 m nh4cl and 0.10 m nh3