Answer:
The correct answer is 27.764 grams.
Explanation:
A standard scientific unit for determining the large quantities of very small entities like molecules, atoms, or other specific particles is termed as a mole. The molecular weight of lithium is 6.941 grams per mole. Thus, one mole of lithium has 6.941 grams.
If, 1 mole of Li has 6.941 grams, then 4 moles of Lithium will have,
= Molecular mass of lithium/1 mole * 4 mole
= 6.941 gram per mole/1 mole * 4 moles.
= 27.764 grams
A positive acceleration indicates that the object sped up. This means that if you compare the first speed to the second, the second speed should be higher.
A negative acceleration indicates that the object has slowed down. This means that if you compare the first speed to the second, the second speed should be lower.
If an acceleration is 0, it means that it neither slowed down nor sped up.
Now let us analyze your problem by listing down the speed and the time:
At noon: 4 mi/hr
12:30 : 6 mi/hr
2:30 : 2 mi/hr
From noon to 12:30, you will notice that there is an increase in speed. This means that Tommy had a positive acceleration. (Rules out D.)
From 12:30 to 2:30, there is a decrease in speed. This would indicate that Tommy had a negative acceleration. (Rules out C.)
No speed was the same, so acceleration was never 0. (Rules out A.)
From the assumptions above, we can now deduce that the answer is B.
Answer:
22.989769 u
Explanation:
The atomic weight of any atom can be found by multiplying the abundance of an isotope of an element by the atomic mass of the element and then adding the results together. This equation can be used with elements with two or more isotopes: Carbon-12: 0.9889 x 12.0000 = 11.8668. Carbon-13: 0.0111 x 13.0034 = 0.1443.
Since there is one mole of Ca^2+ in calcium acetate, its concentration is 0.80 mol/L.
<h3>What is concentration?</h3>
The term concentration has to do with the amount of substance in solution. The concentration can be measured in several units. Generally, concentration is expressed in molarity, molality, mass concentration units or percentage.
Now we are asked to find the amount concentration of calcium ions and acetate ions in a 0.80 mol/L solution of calcium acetate. The formula of calcium acetate is Ca(CH3COO)2.
Thus;
Ca(CH3COO)2(aq) ----> Ca^2+(aq) + 2CH3COO^-(aq)
It then follows that since there is one mole of Ca^2+ in calcium acetate, its concentration is 0.80 mol/L.
Learn more about concentration:brainly.com/question/10725862
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