1. is anybody can help me with this question plz

At sea level, there are approximately 2.6 × 1025 molecules m-3 of the atmosphere.
One of the gases making up the atmosphere has a concentration of 2.21 × 1022 molecules m-3. What is the concentration of this gas expressed in parts per million (ppm)?
The concentration of this gas ={(2.21× 1022)/(2.6× 1025)}×(1× 106
=850 ppm
Superscript (↑)

2.

3. ??

4. This looks like homework. We don't just answer those off the cuff. The 2nd table units don't make sense--check that.

Show you've done some work and thinking about it.
What's confusing you?

5. Originally Posted by vanya
is anybody can help me with this question plz

At sea level, there are approximately 2.6 × 1025 molecules m-3 of the atmosphere.
One of the gases making up the atmosphere has a concentration of 2.21 × 1022 molecules m-3. What is the concentration of this gas expressed in parts per million (ppm)?
The concentration of this gas ={(2.21× 1022)/(2.6× 1025)}×(1× 10^6 )

=850m^-3
is that correct

plz help

6. is anybody online

7. Here's a hint.

If you want to calculate 4.2% of something, you don't just multiply by 4.2.

What does "per cent" mean - and what extra step would that require for the calculation of 4.2% of a number?

Now review what you're trying to do with the problem you've got.

Here's a hint.

If you want to calculate 4.2% of something, you don't just multiply by 4.2.

What does "per cent" mean - and what extra step would that require for the calculation of 4.2% of a number?

Now review what you're trying to do with the problem you've got.

i did not get it please if you explain it again please

9. At the risk of making a fool of myself, here's my novice attempt.

Let's take a number; say 5000. And a percentage increase of 5%.

5% = 5/100 = 0.05

5% of 5000 = 5000 x 0.05 = 250

An increase of 5% of a number 5000 means 5000+250, which gives us 5250. Or if you prefer a more straight forward multiplication, 5% increase means to multiple a number by 1.05. Therefore, an increase of 4.2% means to multiple by 1.042.

2000 increase by 4.2% = 2000 x 1.042 = 2084. Of which the increase was 84.

edits: To go a step further,

Year 1: 200
Year 2: 350
...
Year 10: 730

The % increase between Year 1 to Year 2 is 175%
(350/200) x 100 percent = 175%

The % increase between Year 2 to Year 10 is 208.57%
(730/350) x 100 percent = 208.57%

10. OK. Per cent means per hundred.

So 4.2% = 4.2/100 or 4.2 divided by 100.

Dividing by a hundred is the same as multiplying by 0.01.

As a number therefore, 4.2 per cent = 0.042 .

Clearly, from this, the calculation you showed at #4 would be rewritten as 0.042*1630.

The answer to that is 68.46, not 6846. (Unless you're using some form of notation I'm not familiar with.)

See next item for calculating an increase as a percentage.

11. OK, I'll give an example other than the problem you're set.

At year 1950, a car costs \$1500.
At year 1980, a car costs \$7500.

What is the percentage increase? Think for a minute about how you do this.
================================================== =======

The first thing to look at is the increase in terms of the item given, dollars.

The increase between 1950 price and the 1980 price is \$7500 - \$1500 = \$6000

Do you know what to do next?
================================================== =====

If you were my student, I would have taken your calculator and your phone from you and told you that you could only use them when I handed them back to you for a specific calculation.

At this point in working out a problem, there is no point in using any calculator. You have to be certain that you know what you are calculating.
-----------------------------------------------------------------------------------------
In this case, it's pretty clear that you're simply calculating what one number is as a percentage of another number.

So which numbers from the calculation 7500 - 1500 = 6000 go into the calculation. What is the calculation?

================================================== ==============

Happily, the increase, \$6000, is exactly 4 x \$1500, the original value.

What is the whole number 4 as a percentage? It's 400%

Look back through this a couple of times. Then see if you can apply it to the problem you've got - keep the calculator until last to check your thinking.

6981-1630=5351
5351/1630=3.2828
3.2828×100=328%

13. Nice work. Perfect!

Keep it up.

14. thanks guys for your help.

15. anyone can help me with the first question please

16. First question?

A lot of people have trouble working with numbers like this. Sometimes it's easier to separate out the "number" part from the "power" part to get a handle on the size of the answer you're looking for.

Rewrite as two separate calculations and put them back together afterwards.

{(1022)/( 1025)}×(1× 106) x {(2.21 )/2.6 }×(1)

Does that work better?

17. the answer will be 850 ppm but there is
Superscript (↑ under the question maybe because of that the answer will be incorrect if you know how to do it please

18. No. The answer isn't 850 ppm on that calculation.

Work it through step by step.

19. Sorry - I was working on something else at the same time. Your result is right on the calculation you gave.

But there is something very, very odd about some of those numbers. Is this something from a textbook or from your teacher?

20. ???????

• 21.1×10^22/2.6×10^25=0.85×10^-3 ×1000000=850×10^-6

21. I wrote the answer as =850ppm (thats all i put) but it came back as: my answer was incorrect in some way. It also stated that i may be required to use superscript.

22. now i know the answer thanks guys

23. anyone can help me with this 2 question please

the two scenarios that could possibly lead to no overall change in GMST in this way.

1· The atmospheric CO2 concentration decreases while the albedo of the surface (which isn't covered by ice and snow) increases.

2· The atmospheric H2O concentration increases while the solar constant decreases.

3· The albedo of the surface (which isn't covered by ice and snow) increases while the fraction of Earth's surface covered with ice and snow decreases.

4· The fraction of Earth's surface covered with ice and snow decreases while the atmospheric H2O concentration increases.

5· The volcanic aerosol content in the atmosphere decreases while the fraction of Earth's surface covered with ice and snow decreases.

??

24. For question 2, start here. Greenhouse gas - Wikipedia, the free encyclopedia

Then you need to check the physical structure of each gas you're considering. If a molecule isn't affected by infrared, then it can't be a greenhouse gas. Molecules Vibrate

If it's monatomic or a simple bonded molecule - then it can't function as a greenhouse gas.

25. ????????????????????

26. Here's the IPCC list of greenhouse gases and ozone depleting compounds. IPCC list of greenhouse gases - Wikipedia, the free encyclopedia Only one gas on the IPCC list appears in the problem you've been given.

So clearly you're being asked to look at the structure and properties of the molecules listed.
NO is a minor ozone depleting gas. Nitric oxide - Wikipedia, the free encyclopedia
Br2. Bromine compounds are extreme ozone depleting gases (we're lucky that we used chlorine based CFCs commercially rather than bromine based BFCs - we wouldn't have had a chance to do anything about ozone because it would have been all gone) Bromine - Wikipedia, the free encyclopedia Why are bromine molecules different from the simple molecules of O2 and N2? If they're not different, then this simple diatomic molecule couldn't be a greenhouse gas because it lacks the same features as oxygen and nitrogen.

Look at a couple of the others that have non-neat structures, like say, ammonia.. And check their properties to see if they'd be better candidates.

I strongly recommend a good long look at the site I gave you earlier. Molecules Vibrate

Check your thinking against the information and see how you approach the problem now.

27. I wonder if it can be done that Adelady gets an auto *Like* from me every time she posts? Would save me lots of time.

28. thanks i know the answer

plz help

30. help plz

The planet Mercury has a mass of 3.302 × 1023 kg and a density of 5.43 × 103 kg m–3. Use this information to calculate the volume of Mercury.
Volume,

v=mass/density

You should give your answer in scientific notation to the appropriate number of significant figures and with the correct SI units.
Volume of planet Mercury = 3.302× 1023 kg/5.43 × 103 kg m–3
v =6.1× 1025 m–3

Superscript (↑)

(Your mistake is one reason why I much prefer E-notation)

32. ( 3.302/5.43)=0.61, (1023/ 103 )=10^20
v=0.61
× 1020 m–3

33. Close.

What units are density?

34. its kg
i think you will cancel the kg,
v=0.61× 10^20 m^3