TIESULUI
Carboniferous
Jurassic
Thassic
Permian
Pennsylvanian
Mississippian
Devonian
Silurian
Ordoviciantes
Cambran
Precambrian
Paleozoic
Which method is most likely used to identify what happened before the start of the Paleozoic era?
O
Scientists study fossils from the Jurassic period.
Scientists observe index fossil records of the Mesozoic era.
Scientists examine fossil evidence during the Precambrian time
Scientists explore the emergence of mammals and humans in the Cenozoic era.

Maria wants to determine which type of disinfectant kills the most bacteria. which of the following is the best way for maria to determine this? a. ask ten different companies that make disinfectants which type is best. b. put the same amount and species of bacteria on ten identical plates, and add ten different kinds of disinfectant to each plate. c. interview ten different people to determine which type of disinfectant they prefer. d. put the same amount and species of bacteria on ten identical plates, and add a different disinfectant to each plate.

The vapor pressure of ethanol is 1.00 × 102 mmhg at 34.90°c. what is its vapor pressure at 61.61°c? (δhvap for ethanol is 39.3 kj/mol.)

How does a sample of helium at 15 degree celsius compare to a sample of helium at 215 k? a) the helium at 15 degrees celsius has a higher average kinetic energy that the sample at 215 k. b) the helium at 15 degrees celsius has lower nuclear energy that the sample at 215 k. c) the helium at 15 degrees celsius has slower- moving atoms that the sample at 215 k. d) the helium at 15 degrees celsius has smaller atoms than the sample at 215 k.