Select the correct answer from each drop-down menu. When Raymond observes certain natural phenomena, he often forms ideas about their causes and effects. Suppose that Raymond
surmises that leaves change color in autumn due to scarcity of sunlight. In order to test whether his idea is accurate, he must first
construct a falsifiable
that defines a clear relationship between two variables. Raymond's next step is to
that would isolate and test the relationship between the two variables. This task can be pretty
daunting because Raymond will need to identify and eliminate any
variables that could confuse test results.

Ascientist measures the speed of sound in a monatomic gas to be 449 m/s at 20∘c. what is the molar mass of this gas?

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?

Answer asap need by wednesday morning explain how a buffer works, using an ethanoic acid/sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.