# Metric prefix help

1. Jun 6, 2014

### Nerdydude101

I keep trying to find a certain metric prefix but i can't seem to find it, i need to know what prefix makes 2mL into 200_L i believe it is 10^-5 but i can't find that on any charts. Any help is much appreciated!

2. Jun 6, 2014

### SteamKing

Staff Emeritus
It's not clear what you are looking for.

2 mL = 2 milliliters = 0.002 L

the prefix here is 'milli', which means 1/1000.

200 L = 2 hectoliters

the prefix here is 'hecto', which means 100.

In both cases, the base unit is the liter.

It would be meaningless to say 1 MmL, or 1 Mega-milli-liter, which would equal

10^6 * 10^(-3) = 1000 Liters

3. Jun 6, 2014

If 10^-2 meters is a centimeter and 10^-3 is a millimeter then what is 10^-5 meters.
What I found is centimilli is the prefix before micro and decimilli precedes that

4. Jun 6, 2014

### SteamKing

Staff Emeritus
5. Jun 6, 2014

Micro is 10^-6

http://www.chemteam.info/Metric/Metric-Prefixes.html

The URL for the image says it's from Berkeley for what ever that is worth

Last edited by a moderator: May 6, 2017
6. Jun 6, 2014

### SteamKing

Staff Emeritus
They do a lot of weird things at Berkeley.

http://www.bipm.org/utils/common/pdf/si_brochure_8_en.pdf

On p. 122 of the document above, compound prefixes are expressly prohibited.

I looked at your link but could not find the table reproduced in Post #5. Perhaps someone hacked the page, which has now been fixed.

7. Jun 6, 2014

### dauto

That prefix doesn't exist. That table from Berkley is unorthodox.

8. Jun 6, 2014

### dauto

I went to the page but didn't see any of the unorthodox prefixes.

9. Jun 6, 2014

### Staff: Mentor

That's because the table is given here: http://chemistry.berkeley.edu/links/weights/metric.php [Broken]

(Not that I am saying it is correct, just clarifying what the chrisbradysr was talking about).

Last edited by a moderator: May 6, 2017
10. Jun 6, 2014

### SteamKing

Staff Emeritus
It just goes to show that anyone can post anything on the Internet.

Anywho, we should be past appeals to authority in this case. Combined prefixes are not allowed in SI, period, and Berkeley is doing their students a disservice when teaching them SI with unconventional prefixes, IMO.

11. Jun 6, 2014

I just simply gave a prefix for what he asked. I never said it was universally accepted. Which is why below I said "for what ever it's worth"

12. Jun 7, 2014

### SteamKing

Staff Emeritus
That's why at PF we like to point out these things in our replies, because there are some members who, as students, may not realize that something is not universally accepted. On occasion, we get people trying to disseminate certain ideas (like perpetual motion) and other crackpottery, which is against forum rules.

Now, I can't say what passes for science in the august halls of Berkeley, but I am surprised that such clearly non-standard applications of the SI unit convention are apparently so current that they have crept into the website of the Chemistry Department there.

13. Jun 7, 2014

### 256bits

Well, they ( Berkeley ) do say it is metric, with no mention of it being as accepted SI.

The pdf, though, continues to also say that cc is not the accepted way to write a unit of volume, but that has been around for ages.

I guess their ( the pdf ) main concern is to have anything written to be void of confusion. Is a centimilli necessary. It is confusing just by looking at it.

14. Jun 7, 2014