Need an answer by 11:55, struggling with Chemistry hw

How can a scientist assess whether a pure niobium (nb) sample is responsible for contaminating the lab with radioactivity? test the niobium sample to see whether it now contains other elements. test the niobium sample for the presence of niobium oxide compounds. heat the niobium, and see if the level of radioactivity in the lab increases. place the niobium under pressure, and see if the level of radioactivity in the lab increases.

Solve the problems. express your answers to the correct number of significant figures. 0.09 + 1.324 = 41.0 + 78.3 =water drips from a faucet at a rate of 41 drops/minute. assuming there are 15,000 drops in a gallon, how many minutes would it take for the dripping faucet to fill a 1.00‑gallon bucket? express your answer to the correct number of significant figures. how many minutes to fill the bucket.

At a given temperature, the vapor pressure of heptane is 92.0 torr and the vapor pressure of octane is 31.2 torr. assuming ideal behavior, what is the vapor pressure of a solution that contains three times as many moles of octane as heptane?