The answer is C
Why:
A - this is natural
B - water is natural
D - this is also natural
C- this is right because when we breathe out we produce more carbon dioxide then we breathed in.
Answer:

Explanation:
When you form a <em>diluted solution</em> from a mother (concentrated) solution, the moles of solute are determined by the mother solution.
The main equation is:

Then, since the moles of solute is the same for both the mother solution and the diluted solution:

Substitute and solve for the molarity of the diluted solution:

<u>Answer:</u> The red litmus paper turns blue on dipping in NaOH solution.
<u>Explanation:</u>
Litmus paper is the indicator that detects the nature of the solution, whether it is acidic or basic.
There are 2 types of litmus paper:
- <u>Red litmus paper:</u> This paper will turn blue if it is dipped in basic solution and will remain as such if it is dipped in acidic solution.
- <u>Blue litmus paper:</u> This paper will turn red if it is dipped in acidic solution and will remain as such if it is dipped in basic solution.
NaOH is a strong base, so when a red litmus paper is dipped in the beaker having necessary amount of NaOH, the red litmus paper turns into blue.