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Scientific notation/ exponents? (AVAGADROS CONSTANT)

Can anyone help me understand scientific notation better. I'm trying to understand avagadro's constant at the moment (6.02* 10^23) but I'm confused on the whole 10^ 23 exponent thing.

The base 10, and whatever exponent seem to crop up everywhere.

1g=1000mg or 1mg=10-3 g or 1g=1000000000ng or 1ng=10-9 g

How do you work these out? ^^^ (I'm asking incase I have to find a different unit in the exam)


This is slightly confusing for me, at GCSE exponents were not ever taught that well to me. Can anyone help me out please? could you explain them please?
Original post by ChemistryAShelp!
Can anyone help me understand scientific notation better. I'm trying to understand avagadro's constant at the moment (6.02* 10^23) but I'm confused on the whole 10^ 23 exponent thing.

The base 10, and whatever exponent seem to crop up everywhere.

1g=1000mg or 1mg=10-3 g or 1g=1000000000ng or 1ng=10-9 g

How do you work these out? ^^^ (I'm asking incase I have to find a different unit in the exam)


This is slightly confusing for me, at GCSE exponents were not ever taught that well to me. Can anyone help me out please? could you explain them please?


it's mainly used as a way of writing very large and very small numbers without needing to use lots of zeros.

if you consider the low powers of 10

100=1.0
101=10.0
102=100.0
103=1000.0

and on the negative
10-1=0.1
10-2=0.01
10-3=0.001

you can see the pattern... subtracting 1 from the exponent hops the decimal point left by one numeral, adding 1 to the exponent hops the decimal right by one numeral.
so 1023 is just 1 with the decimal point hopped right by 23 places, to write it out longhand it'd be 1 followed by 23 zeros.
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Jpw1097
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Original post by ChemistryAShelp!
Can anyone help me understand scientific notation better. I'm trying to understand avagadro's constant at the moment (6.02* 10^23) but I'm confused on the whole 10^ 23 exponent thing.

The base 10, and whatever exponent seem to crop up everywhere.

1g=1000mg or 1mg=10-3 g or 1g=1000000000ng or 1ng=10-9 g

How do you work these out? ^^^ (I'm asking incase I have to find a different unit in the exam)


This is slightly confusing for me, at GCSE exponents were not ever taught that well to me. Can anyone help me out please? could you explain them please?


It is standard form. Avogadro's constant, 6.02x1023 just means 6.02 x 1023 (which is 1 with 23 zeros after it) which is 60,200,000,000,000,000,000,000.

For example 2x109 just means 2 multiplied by 109 (i.e. 1 with 9 zeros after it, so 1,000,000,000) which would be 2,000,000,000.

1400 is 1.4x103. it is 1.4 multiplied by 103 (1 with 3 zeros after it, which is 1000). 1.4 x 103 = 1.4 x 1000 = 1400.

Standard form is just away of expressing extremely large or extremely small numbers in a simple way. It would be very annoying to have to write 60,200,000,000,000,000,000,000 every time we wanted to write Avogadro's constant, so instead we write this in standard form, 6.02x1023.

As you have said, 1g = 1000mg OR you could write this as 1g = 103mg.
If one thousand milligrams is equal to one gram, then one milligram is equal to one thousandth of a gram.
So 1mg = 0.001g (thousandth of a gram)
This can be written as 1mg = 10-3g. The minus 3 means there are 3 numbers before the 1.

If you are still unsure then have a look at this website
http://www.bbc.co.uk/schools/gcsebitesize/maths/number/powersrootshirev1.shtml


Hopefully this helps you out a bit with standard form.

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