Software question regarding Google Chrome and Firefox (I am not asking which is best)

I read Chrome is supposed to be basic and less resource hungry so I downloaded it and installed it. It is very fast but I have two issues with it. The first is how it does not warn you if you are going to close multiple tabs (I've heard the PC version just added the feature a week ago but who knows?). The bigger issue is that Chrome is ungodly resource hungry or I just do not know how to read a computer...it shows at any given moment that at least 6 Google Chrome processes are running and they take up substantial memory. Below is a pic of the activity monitor (there are 4 more Google processes lower down which I couldnt photo). Is this right because it indicates Google uses over 5 times the resources of Firefox?

Tab wise I when running I had the same number of tabs open and identical websites on a few comparisons. The two things I saw was that:
1) Google Chrome uses less resources with 1-2 tabs, Firefox uses less and less as the number of tabs increase
2) Google add-ons seem to each add on a process that utilizes a decent amount of RAM where as Firefox add-ons do not use this much memory

I wasn't sure if it was problematic or not; when I use Firefox and have 20+ tabs open (research) and Word, Excel, SPSS, Activity Monitor, Paint, Email, and PDF viewer running I still have over a 1gb of memory free; when I did with this Google Chrome I only has about 150mb free; is this an issue?

Oh and at the time I was running:
-You Tube running a music video
-This forum (w00t!)
-OWC's How To portion of their website
-Pub Med, Google Scholar, EBSCO, AJS, and a few other research sites with a total of about 10 tabs each representing one journal article or abstract of the article

That's all pretty normal for me...well except the forum but I'm here more often now as I've learned so much