+0  
 
+3
1485
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and i may need mathematics assistance later in the year 

off-topic
 Oct 19, 2017
 #1
avatar+450 
+2

Ok, shoot, and I will see what I can do for you. (I am certified to tutor math for Kindergarten- 4th grade.) But I do enjoy higher grade math challenges! 

 Oct 19, 2017
 #2
avatar+470 
0

"The mass of a dust particle is approximately 7.5x10^-10 kilograms and the mass of an electron is 9.1x10^-31 kilograms. Approximately how many electrons have the same mass as one dust particle?"

 

(X stands for multiplication in this case)

Neptune  Oct 19, 2017
 #3
avatar
+2

Just divide one by the other. Why did you ask your question in the "Answers" section instead of in the "Questions" section?

(7.5 x 10^-10) / (9.1 x 10-31) =8.24 x 10^20 electrons in 1 mote of dust.

 Oct 19, 2017
 #4
avatar+106943 
+4

"The mass of a dust particle is approximately 7.5x10^-10 kilograms

and the mass of an electron is 9.1x10^-31 kilograms.

Approximately how many electrons have the same mass as one dust particle?"

 

This is just a division problem. You want electrons are in each dust particle

So how many times 9.1x10^-31 kilograms. goes into 7.5x10^-10 kilograms

 

7.5x10^-10 kilograms      divided by     9.1x10^-31 kilograms 

 

(7.5x10^-10) / (9.1x10^-31)  

=(7.5/9.1) * (10^-10 / 10^-31) electrons per particle

 

(7.5/9.1) = 0.8241758241758242 = 8.241758241758242*10^-1

(10^-10 / 10^-31) = 10^21

 

So tha answer is   

\(\approx 8.24\times 10^{-1}\times 10^{21}\\ \approx 8.24\times 10^{20}\;\;\text {electons in one dust particle}\)

.
 Oct 19, 2017

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