Answer:
[Unfortunately] Answer is A
Explanation:
You should know that 'liquid' is a state of matter and aqueous means that there is water present.
-It is mentioned that barium chloride is a <u>solution</u>. So you can cut off the C option.
-Barium sulfate is a <u>salt</u> which means it's a solid, so you can cut off the D option.
We now have A and B as the only options remaining.
-Dilute sulfuric acid is definitely not a liquid because water is present. (dilute indicates that there is a greater proportion of water)
The answer should be A.
Answer:
There is one single covalent bond between two carbon atoms.
Explanation:
We know that sharing of electrons form covalent bonds.
If we look upon K,L,M ,N shells of the carbon and hydrogen atoms.
We found that Hydrogen is having only 
electron in K shell.
And Carbon on the other hand is having 
electrons in K shell and 
electrons in L shell.
So carbon have valence electrons,and it can share bonds with any relevant atom to complete its octet.
And Hydrogen requires electron to complete its doublet.
Alkane general formula 
For ethane 
Carbon atom is shared by 
Hydrogen.
The remaining one electron 
of carbon will be shared with another carbon atom.
An image of the sharing of electrons attached below,
Hence we have only covalent bond between the two.
Answer:
The answer is
D. Main sequence
Explanation:
Main sequence stars can be between one thousand times dimmer and one million times brighter than the Sun.
What is main sequence stars?
A main sequence star is any star that is fusing hydrogen in its core and has a stable balance of outward pressure from core nuclear fusion and gravitational forces pushing inward.
Ok let me explain the procedure to you:
The buffer solution is like this:
pH = pKa + log [salt]/[acid]
4 = 4.20 + log [salt] / [acid]
-0.20 = log [salt]/[acid]
If you <span>Solve for [salt]/[acid]
This gives ratio of moles.
</span><span>Take amount of acid be x L and then amount of salt will be 0.1-x
Now molarity*volume=number of moles
</span>I know that with this you will be able to get to the result. Hope this helps
