The mass of a uranium nucleus = 3.92×10–25kg?

3.92x10^-25kg means: 0.0000000000000000000000000392kg.

The '-25' is usually shown is a smaller font size above the '10' and effectively means you are moving the decimal point 25 places to the left (ie the number is small).

Reply 3

Its

3.92(10^{-25})

10^{-25} = \dfrac {1}{10000000000000000000000000}

giving us

3.92( \dfrac {1}{10000000000000000000000000}) kg

Reply 4

Princess Bubbles

16

Duckzilla

What does this mean? Is it 3.92 multiplied by 10 then minus 25, or is it a boundary between 10 and 25 multiplied by 3.92, or something else? A Google search told me this was the mass of a uranium nucleus, I need to know for my summer homework :smile:

It's standard form.

http://www.mathsrevision.net/gcse/pages.php?page=43

Reply 5

M_E_X

10^-5 is a bit more complicated: it is one divided by ten times ten, or 1/100

Sorry to be pedantic but 10^-5 is 1000, ie: -
1/10000

Reply 6

StructuralEngineer

Sorry to be pedantic but 10^-5 is 1000, ie: -
1/10000

Sorry to be pedantic but

10^{-5} = 0.00001

ie:-

\dfrac{1}{100000}

Reply 7

Johan C

13

Times 10 to the power -25, which is times 1 over 10 to the power 25.

Reply 8

jonathan3909

Sorry to be pedantic but

10^{-5} = 0.00001

ie:-

\dfrac{1}{100000}

Oh, looks like we both made a mistake:

10^-5 is .0001

Ie. 1/10000 of the original value (which is 10, not 1).

Reply 9

StructuralEngineer

Oh, looks like we both made a mistake:

10^-5 is .0001

Ie. 1/10000 of the original value (which is 10, not 1).

No.I did not make any mistake.You're forgetting some basic maths here :wink:

0.0001 = 10^{-4}

ie.

10^{-5} = \dfrac {1}{10^{5}} = 0.00001

Wake up.Its simple maths :smile:

Reply 10

jonathan3909

No.I did not make any mistake.You're forgetting some basic maths here :wink:

0.0001 = 10^{-4}

ie.

10^{-5} = \dfrac {1}{10^{5}} = 0.00001

Wake up.Its simple maths :smile:

No, this is not right ie.

Although I suspect you are talking about the reduction factor and I about the end result.

you say 0.0001=10^-4, this is not correct for an absolute answer,
0.0001 is the reduction factor (you are reducing the number by a factor of ten-thousandth), but it is reducing '10' not '1' so the answer is 0.001 hence one, ten-thousandth of the original value of 10.

Reply 11

suneilr

3

StructuralEngineer

No, this is not right ie.

Although I suspect you are talking about the reduction factor and I about the end result.

you say 0.0001=10^-4, this is not correct for an absolute answer,
0.0001 is the reduction factor (you are reducing the number by a factor of ten-thousandth), but it is reducing '10' not '1' so the answer is 0.001 hence one, ten-thousandth of the original value of 10.

10^{-4} = \frac{1}{10^4} = 0.0001

Reply 12

Stonebridge

13

10^-4 =0.0001 [=1/10000]
10^-3 =0.001 [=1/1000]
10^-2 =0.01 [=1/100]
10^-1 =0.1 [=1/10]
10^0 = 1
10^1 =10
10^2 =100
10^3 =1000

etc

Reply 13

trm90

12

Duckzilla

What does this mean? Is it 3.92 multiplied by 10 then minus 25, or is it a boundary between 10 and 25 multiplied by 3.92, or something else? A Google search told me this was the mass of a uranium nucleus, I need to know for my summer homework :smile:

If you know how exponents etc work, well, 10^10 or 10^25 kg is obviously wayyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy too heavy for a Uranium nucleus, so yeh it's just 3.92x10^-25kg

Reply 14

Just got out of bed and re-read what I wrote, and yes, I was way wrong. Sorry people, back to school for me.

Reply 15

StructuralEngineer

Just got out of bed and re-read what I wrote, and yes, I was way wrong. Sorry people, back to school for me.

I'm glad you get it now :smile:

Reply 16

Cora Lindsay

10

Sorry to be a pain but the nuclei of different uranium isotopes will have slightly different masses

Reply 17

the.real.McKay

Cora Lindsay

Sorry to be a pain but the nuclei of different uranium isotopes will have slightly different masses

It would have a different Mass Number due to a different number of nucleons (more neutrons but same protons), so yes.

(I think)

Reply 18