You got 19 out of 22!

Dear Quizly, In the above quiz:
“This Science Quiz will be Extremely Hard for Everyone Except Those with Seriously High IQ”, in Question 2: When asking which gas is the most abundant in our atmosphere, you wrote the following in your answer:
“The correct answer is “Nitrogen”. The atmosphere is almost 80% nitrogen and 20% oxygen with about 5% of the atmosphere being comprised of other gases. The five layers of the atmosphere are the exosphere, thermosphere, mesosphere, stratosphere and troposphere.”
But the percentages you quoted above are incorrect, as you should have realised, because they add up to 105%!! Obviously, the total number of gases in the atmosphere cannot add up to more than 100% of the whole of it! Actually, rounded to the nearest positive integer (whole number), in a completely DRY atmosphere, Nitrogen constitutes 78% of it, Oxygen, 21%, and the remaining 1% is comprised of many other gases, including argon & carbon dioxide, and then tiny amounts of Neon, Helium, Methane, Krypton, Hydrogen, Nitrous Oxide, Carbon Monoxide, Xenon, Ozone, Nitrogen Dioxide, Iodine & Ammonia.
The percentages quoted above apply only if the atmosphere is completely dry, but, as water vapour is nearly always present, making UP TO 4% of the total volume of our atmosphere, the more of it there is, the more the percentages of all the other gases will be reduced (i.e. proportionately).
SEE: https://www.noaa.gov/jetstream/atmosphere