Argon is a noble gas. Argon has a full outer shell. This makes it so that it does not need to react with any of the other elements to be stable.
With Rubidium and Cobalt its a whole different story.
I hope that helps!
Answer:
Helium has atomic mass 4.002602.
So the answer to yr question is helium.
False. What you’re describing is a displacement reaction.
Answer:
Cost to supply enough vanillin is 
Explanation:
Threshold limit of vanillin in air is
per litre means there should be
of vanillin in 1L of air to detect aroma of vanillin.

So, 
So amount of vanillin should be present to detect = 
As cost of 50 g vanillin is
therefore cost of
vanillin = 
C is the answer because he wants to know if less force is needed to pull on a slippery surface which reduces friction