An atom of strontium-90 contains how many electrons, protons, and neutrons?
38e⁻, 38 protons, and 52 neutrons
Explanation:
Mole ratio of NH3 to NaNH2 = 2 : 2.
Moles of NaNH2 produced
= 4.3mol * (2/2) = 4.3mol.
1 μL = 10^-6 L by definition
So...
82 μL = 82x10^-6 L = 8.2x10^-5 L
Answer:
After 9.0 hours
Explanation:
Using the decay equation, we can write the amount of drug propanol after time t as:
(1)
where
m(t) is the mass left at time t
is the initial mass of the substance
is the decay constant
t is the time
The decay constant is related to the half-life of the substance as follows:
where is the half-life.
Here we have
So the decay constant is
We want to find the time t after which the dose is 80% of the initial dose is eliminated, so the time t after which 20% of drug is left, so
Substituting eq(1) and solving for t, we find:
Answer:
In a controlled experiment, an independent variable (the cause) is systematically manipulated and the dependent variable (the effect) is measured; any extraneous variables are controlled. State what steps you will take to design an experiment to test your hypothesis. Complete the experiment. Make observations. Record what happened during your experiment.