Answer:
B it reduces the need for fossil fuels
Explanation:
I got the answer wrong and it showed B was the right one
the force between the electron and the proton.
a) Use F = k * q1 * q2 / d²
where k = 8.99e9 N·m²/C²
and q1 = -1.602e-19 C (electron)
and q2 = 1.602e-19 C (proton)
and d = distance between point charges = 0.53e-10 m
The negative result indicates "attraction".
the radial acceleration of the electron.
b) Here, just use F = ma
where F was found above, and
m = mass of electron = 9.11e-31kg, if memory serves
a = radial acceleration
the speed of the electron.
c) Now use a = v² / r
where a was found above
and r was given
<span> the period of the circular motion.</span>
d) period T = 2π / ω = 2πr / v
where v was found above
and r was given
Answer:
All chemical reactions need energy to get started. Even reactions that release energy need a boost of energy in order to begin. The energy needed to start a chemical reaction is called activation energy.
Explanation:
D. Has a uniform composition and is only able to be separated by chemical means.
1978 to 2004 is <em>26 years</em>.
Every 5.23 years, half of our 200-gram sample decays.
It has reached its half life ~4.97 times.
We use this formula to find our new amount:
![200\times(\frac12)^\frac{26}{5.23}](https://tex.z-dn.net/?f=200%5Ctimes%28%5Cfrac12%29%5E%5Cfrac%7B26%7D%7B5.23%7D)
Every time it reaches its half life, it will be halved...the fractional exponent there is to pick up minute differences like in our 4.97.
![200\times(\frac12)^{4.97131931}](https://tex.z-dn.net/?f=200%5Ctimes%28%5Cfrac12%29%5E%7B4.97131931%7D)
![200\times0.0318774644](https://tex.z-dn.net/?f=200%5Ctimes0.0318774644)