We know the formula of the density:
ρ =

;
So the mass will be equal to:
m = ρ * V = 2.70 * 21.3 = 57,51 g =
57510 mg of substance.
So the answer is 57510.
Answer:
option C is correct (250 g)
Explanation:
Given data:
Half life of carbon-14 = 5700 years
Total amount of sample = 1000 g
Sample left after 11,400 years = ?
Solution:
First of all we will calculate the number of half lives passes during 11,400 years.
Number of half lives = time elapsed/ half life
Number of half lives = 11,400 years/5700 years
Number of half lives = 2
Now we will calculate the amount left.
At time zero = 1000 g
At first half life = 1000 g/2 = 500 g
At second half life = 500 g/2 = 250 g
Thus, option C is correct.
Answer:
Answers are in the explanation
Explanation:
Based on the reaction:
CF₄ + 2Br₂ → CBr₄ + 2F₂
The mole ratio of CF₄ is:
CF₄:Br₂ = 1:2
CF₄:CBr₄ = 1:1
CF₄:F₂ = 1:2
<em>Moles F2:</em>
Molar mass CF₄: 88.0g/mol
57.0g * (1mol / 88.0g) = 0.6477 moles CF₄ * (2mol F₂ / 1mol CBr₄) =
<h3>1.30 moles F₂</h3><h3 />
<em>Mass Br2:</em>
Molar mass CBr₄: 331.63g/mol
250.0g * (1mol / 331.63g) = 0.7539 moles CBr₄ * (2mol Br₂ / 1mol CF₄) =
1.51 moles Br₂ * (159.808g / mol) =
<h3>241g Br2</h3><h3 /><h3 />
<em>Moles F2:</em>
4.8 moles CF₄ * (2mol F₂ / 1mol CF₄) =
<h3>9.6 moles F₂</h3><h3 />
<em />
Answer:
D. Black Holes
Explanation:
Black holes are large objects that form dense gravity wells in space. Their gravitational pull is so strong that even light cannot escape it.