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Number of moles is defined as the ratio of given mass in g to the molar mass.
The mathematical formula is:
Number of moles = 
(1)
Number of zinc atoms is equal to 
, by Avogadro number, number of moles can be calculated.
As, 1 mol=
atoms, hence,
= 0.2822 mol
Now, from formula (1), calculate mass in g (molar mass of zinc = 65.4 g/mol)
0.2822 mol = 
mass in g = 
= 18.45588 g
Thus, by rounding off the above number, it will come near about 19 g approximately.
Hence, option (C) is the correct answer.
Answer:
16 neutrons
Explanation:
now that protons are equal to electrons, there are 15 electrons. The mass is equal to 31.0, which is the ≡ of protons and ≡ neutrons added together. To find the number of neutrons, subtract the atomic # from the total mass #. 31-15=16 this would be equal to 16 now that the atomic has 31 and the mass is 15 subtract them ... you would get 16 neutrons inside the nucleus.
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It is recommended only for the second type of candy to be taken off the market.
Based on the background information, if a candy shows a 0,62 Rf value in the chromatography it is considered potentially dangerous, and therefore it should be taken off the market.
The Rf value is calculated using the following formula:
- Rf = Total distance traveled by a component/ Total distance from the pencil line to the solvent front
Now, let's find out if any of the components has an Rf equal to 0,62.
Note: To determine the distances I measured the image using a ruler and you can do the same, this will not alter the results.
- Sample 1
- Total distance traveled by the component: 6cm
- Total distance: 7 cm
- Rf : 6 cm/ 7 cm = 0.85
2. Sample 2
- Total distance traveled by the component: 4.34cm
- Total distance: 7 cm
- Rf : 4.34 cm/ 7 cm = 0.62
This means sample 2 has the 0.62 Rf value and therefore it needs to be taken off the market.
Learn more about chromatography in: brainly.com/question/10296715
