<span>440 g
First, determine the volume of each sheet. And it's easier if each dimension is using the same unit of measure. So each sheet is 28 cm by 22 cm by 0.30 cm. Multiply them together
28 cm * 22 cm * 0.30 cm= 184.8 cm^3
Since we have 2 identical sheets, double the total volume
184.8 cm^3 * 2 = 369.6 cm^3
Now multiple the volume by the density
369.6 cm^3 * 1.2 g/cm^3 = 443.52 g
Round the results to 2 significant digits since all of the given figures are only 2 significant digits long.
443.52 g = 440 g</span>
Answer:
9
Explanation:
The structure of fluorophore used in the experiments has been drawn in the attachment. And from the drawing counting we can say that there are 9 sp2-hybridized carbon atoms present. Fiuorophores are a fluorescent chemical compound that can re-emit light upon light excitation. Normally used to produce absorbance and emission spectra.
A volumetric flask is used to contain a predetermined volume of substance and only measures that volume, for example 250 ml.
Conical flasks can be used to measure the volume of substances but the accuracy they provide is usually up to 10ml. Conical flasks are used in titrations, reactions where the liquid may boil, and reactions which involve stirring.
Pippettes are of two types, volumetric and graduated. Pippettes are used where high accuracy is required and volumetric pippettes come in as little as 1 ml. Pippettes are usually used in titrations.
Graduated cylinders come in a wide variety of sizes and their accuracy can be down to as much as 1 ml. They are used to contain liquids.
The important thing in this question is the unit. The mass equals density * volume. 3.1 L = 3.1 * 10^3 cm3. So the mass is 3.193*10^3 g. 1 pound = 453.95 g. So the answer is 7.04 pounds.
d. When aluminum-28 undergoes beta decay, silicon-28 is produced.
Explanation:
When the nuclei of aluminium-28 decays, it produces silicon- 28:
Aluminium ²⁸₁₃Al
Silicon 28 ²⁸₁₄Si
beta particle ⁰₋₁
²⁸₁₃Al → ²⁸₁₄Si + ⁰₋₁
This way, the mass and atomic number are conserved.
Conservation of mass number:
28 = 28 + 0, 28 = 28
13 = 14 -1 , 13 = 13
Learn more:
Balancing nuclear equations brainly.com/question/10094982
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