A joke for nerds

[Warrigal]

There's a reward for the first one that gets it.

Two scientists walk into a bar.

The first scientist says, “I’ll have some H2O.

The second scientist says, “I’ll have a glass of water, too. Wh... why did you say H2O? Like, I know it’s the chemical formula for water and all, but it’s the end of the day and there’s really no need to intentionally over-complicate things like that in a situation outside of work.”

The first scientist stares at his drink, angry that his assassination plan has failed.

 

[Warrigal]

No-one got it yet?
Say after me ... "I'll have a glass of H2O too."

 

[Happyflowerlady]

Hydrogen peroxide , H2O2

 

[Warrigal]

Well done HFL. In it's pure form it is lethal to drink.

Here is your prize http://www.iflscience.com/

 

[Happyflowerlady]

Correct, but when diluted, it is sure good for a lot of things. Since it adds an extra oxygen molecule to the water, it helps to add a dab to water for your plants.
It took me a few minutes; but I was getting ready to post just as you were adding the clue. Excellent riddle ! !
PS, the little Yorkie is cute, too, and I love the picture of the Hyperloop. Elon Musk is a favorite of mine.