Answer:
Option C. 52.057
Explanation:
The following data were obtained from the question:
Isotope >> Mass number > Percentage
A (Cr-50) > 50 >>>>>>>>>> 4.3
B (Cr-52) > 52 >>>>>>>>>> 83.8
C (Cr-53) > 53 >>>>>>>>>> 9.5
D (Cr-54) > 54 >>>>>>>>>> 2.4
Average atomic mass =?
The average atomic mass of chromium, Cr can be obtained as follow:
Average atomic mass = [(Mass of A × A%) /100] + [(Mass of B × B%) /100] + [(Mass of C × C%) /100] + [(Mass of D × D%) /100]
Atomic mass of Cr = [50×4.3)/100] + [52×83.8)/100] + [53×9.5)/100] + [54×2.4)/100]
= 2.15 + 43.576 + 5.035 + 1.296
Atomic mass of Cr = 52.057
Therefore, the atomic mass of chromium, Cr is 52.057
Answer:
growth of plants
Explanation:
The variable which changes on its own is called the independent variable and the variable which changes according to the changes in the independent variable is called the dependent variable.
Here the growth of the plants is observed under light of different colors. So, Suzie is has placed 5 ferns and placed them under different color lights. She also keeps the other factors such as amount of water the plants receive the same. She measures the different color lights have on growth of the plants.
Hence, here the dependent variable is the growth of the plants and the independent variable is the color of the lights.
CU is the element symbol for Copper.
The answer is 1/16.
Half-life is the time required for the amount of a sample to half its value.
To calculate this, we will use the following formulas:
1.

,
where:
<span>n - a number of half-lives
</span>x - a remained fraction of a sample
2.

where:
<span>

- half-life
</span>t - <span>total time elapsed
</span><span>n - a number of half-lives
</span>
So, we know:
t = 10 min
<span>

= 2.5 min
We need:
n = ?
x = ?
</span>
We could first use the second equation to calculate n:
<span>If:

,
</span>Then:

⇒

⇒

<span>
</span>
Now we can use the first equation to calculate the remained fraction of the sample.
<span>

</span>⇒

<span>⇒

</span>
Answer:
0.25L
Explanation:
Using the dilution formula
C1V1=C2V2
C1=6M
V1?
C2=0.75M
V2=2.0L
V1= C2V2/C1
V1=0.75*2.0/6
V1=0.25L