Answer:
strong enough to hold molecules relatively close together but not strong enough to keep molecules from moving past each other.
Explanation:
In liquids, the attractive intermolecular forces are <u>strong enough to hold molecules relatively close together but not strong enough to keep molecules from moving past each other</u>.
Intermolecular forces are the forces of repulsion or attraction.
Intermolecular forces lie between atoms, molecules, or ions. Intramolecular forces are strong in comparison to these forces.
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Answer:
A) Sample B has more calcium carbonate molecules
Explanation:
M = Molar mass of calcium carbonate = 100.0869 g/mol
= Avogadro's number = ![6.022\times 10^{23}\ \text{mol}^{-1}](https://tex.z-dn.net/?f=6.022%5Ctimes%2010%5E%7B23%7D%5C%20%5Ctext%7Bmol%7D%5E%7B-1%7D)
For the 4.12 g sample
Moles of a substance is given by
![n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{4.12}{100.0869}\\\Rightarrow n=0.0411\ \text{mol}](https://tex.z-dn.net/?f=n%3D%5Cdfrac%7Bm%7D%7BM%7D%5C%5C%5CRightarrow%20n%3D%5Cdfrac%7B4.12%7D%7B100.0869%7D%5C%5C%5CRightarrow%20n%3D0.0411%5C%20%5Ctext%7Bmol%7D)
Number of molecules is given by
![nN_A=0.0411\times 6.022\times 10^{23}=2.48\times 10^{22}\ \text{molecules}](https://tex.z-dn.net/?f=nN_A%3D0.0411%5Ctimes%206.022%5Ctimes%2010%5E%7B23%7D%3D2.48%5Ctimes%2010%5E%7B22%7D%5C%20%5Ctext%7Bmolecules%7D)
For the 19.37 g sample
![n=\dfrac{19.37}{100.0869}\\\Rightarrow n=0.193\ \text{mol}](https://tex.z-dn.net/?f=n%3D%5Cdfrac%7B19.37%7D%7B100.0869%7D%5C%5C%5CRightarrow%20n%3D0.193%5C%20%5Ctext%7Bmol%7D)
Number of molecules is given by
![nN_A=0.193\times 6.022\times 10^{23}=1.16\times 10^{23}\ \text{molecules}](https://tex.z-dn.net/?f=nN_A%3D0.193%5Ctimes%206.022%5Ctimes%2010%5E%7B23%7D%3D1.16%5Ctimes%2010%5E%7B23%7D%5C%20%5Ctext%7Bmolecules%7D)
![1.16\times 10^{23}\ \text{molecules}>2.48\times 10^{22}\ \text{molecules}](https://tex.z-dn.net/?f=1.16%5Ctimes%2010%5E%7B23%7D%5C%20%5Ctext%7Bmolecules%7D%3E2.48%5Ctimes%2010%5E%7B22%7D%5C%20%5Ctext%7Bmolecules%7D)
So, sample B has more calcium carbonate molecules.
The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.
3.124mg of I-131 is present after 32.4 days.
The 131 I isotope emits radiation and particles and has an 8-day half-life. Orally administered, it concentrates in the thyroid, where the thyroid gland is destroyed by the particles.
What is Half life?
The time required for half of something to undergo a process: such as. a : the time required for half of the atoms of a radioactive substance to become disintegrated.
Half of the iodine-131 will still be present after 8.1 days.
The amount of iodine-131 will again be halved after 8.1 additional days, for a total of 8.1+8.1=16.2 days, reaching (1/2)(1/2)=1/4 of the initial amount.
The quantity of iodine-131 will again be halved after 8.1 more days, for a total of 16.2+8.1+8.1=32.4 days, to (1/4)(1/2)(1/2)=1/16 of the initial quantity.
If the original dose of iodine-131 was 50mg, the residual dose will be (50mg)*(1/16)=3.124mg after 32.4 days.
Learn more about the Half life of radioactie element with the help of the given link:
brainly.com/question/27891343
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