<span>half-life means you divide by 2
21.6 / 3.6 = 6 hf (hf = half-life)
then you divide by 2^6
6.02 x 10^23 / 2^6 = 9.40625 x 10^21 atoms
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26
3hf ===> 2^3
10.0 / 2^3 = 1.25 gram (remaining)
answer : 10 - 1.25 = 8.75g
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27
128 / 2^n = 2
64 = 2^n
n = 6
24 /6 = 4
4 days is the half-live of the sample
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28
2.5/4.46 of 50% initial mass
(2.5/4.46) x 0.5 x 2 = 0.5605 g
answer: 2 - 0.5605 = 1.4395 g
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29
2^7 = 128
so 7 half-lifes
7* 8040 = 56200 days
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30
the time of 10 half-lifes
= 10 x 0.334s = 3.34s </span><span>
</span>
Answer:
All A to D
Step-by-step explanation:
The attachment completes the question
From the attachment,
- it can be seen that QRS and TUV are of the same i.e. triangles
Also, from the attachment, the sides of each are:
And the angles are:
The above show that QRS and TUV are:
- similar
- same sides
- and they are congruent
Answer:
1 positive solution (and 1 negative)
the greatest solution is about 2.87
Step-by-step explanation:
so, it is
x² + 2x + 7 = 21
x² + 2x - 14 = 0
the general solution to such a quadratic equation is
x = (-b ± sqrt(b² - 4ac))/(2a)
in our case
a = 1
b = 2
c = -14
x = (-2 ± sqrt(2² - 4×1×-14))/(2×1) =
= (-2 ± sqrt(4 + 56))/2 = (-2 ± sqrt(60))/2 =
= (-2 ± sqrt(4×15))/2 = (-2 ± 2×sqrt(15))/2 =
= -1 ± sqrt(15)
x1 = -1 + sqrt(15) = 2.872983346... ≈ 2.87
x2 = -1 - sqrt(15) = -4.872983346...
Answer:
Value is 15 and measure is 151
U^2 - u -30
Hope it helps.
