Answer:
16.6 mg
Explanation:
Step 1: Calculate the rate constant (k) for Iodine-131 decay
We know the half-life is t1/2 = 8.04 day. We can calculate the rate constant using the following expression.
k = ln2 / t1/2 = ln2 / 8.04 day = 0.0862 day⁻¹
Step 2: Calculate the mass of iodine after 8.52 days
Iodine-131 decays following first-order kinetics. Given the initial mass (I₀ = 34.7 mg) and the time elapsed (t = 8.52 day), we can calculate the mass of iodine-131 using the following expression.
ln I = ln I₀ - k × t
ln I = ln 34.7 - 0.0862 day⁻¹ × 8.52 day
I = 16.6 mg
I believe it is the very first one
hope it helps :)
Answer:
Here's what I get
Explanation:
A plant extract is a mixture because it contains different substances: acetone or ethanol, chlorophylls A and B, carotene and xanthophylls.
It is homogeneous because it is a solution. There is only one phase: the liquid phase. You cannot see the pigments as separate phases.
You can separate the pigments by paper, thin layer, or column chromatography.
Many schools use paper chromatography, because paper is cheap.
As the mixture of pigments follows the solvent up the paper, they separate into different coloured bands according to their attractive forces to the cellulose in the paper.
The chlorophylls are strongly attracted to the paper, so they don't travel very far.
The nonpolar carotene molecules have little attraction to the polar cellulose, so they are carried along by the solvent front.
well one thing that’s unique about water is the fact that it’s dipole, meaning that water has both a positive side and a negative side.