M (C2H6) = n × M = 4.6 × 30 = 13.8 g.
Hey there!
A half-life means after a certain amount of time, half of that substance will have decayed after that time.
An equation for exponential decay is the following:
y = a(1 - b)ⁿ
Where a is the original amount, b is the rate of decay, and n is time.
1000 is about 0.3 of a half life, 1000 divided by 138 days (3312 hours) is approximately 0.3.
Let's plug in values to that equation:
y = 321(1 - 0.5)^(0.3)
Simplify.
y = 260.73
There will be 260.73mg of polonium-210 remaining after 1000 hours.
Hope this helps!
Answer:
<h2>9.93 × 10²³ atoms</h2>
Explanation:
The number of atoms of potassium can be found by using the formula
<h3>N = n × L</h3>
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 1.65 × 6.02 × 10²³
We have the final answer as
<h3>9.93 × 10²³ atoms</h3>
Hope this helps you
Answer:
so the earth has an atmosphere, which holds in all the oxygen, it has gravity, and it has the green house effect, causing the earth's warmth to stay in it's atmosphere
