Akpos In A Chemistry Class

In a chemistry class, the teach, the teacher asked the students to name the atmospheric gases:

Musa: oxygen

Teacher: good.

Chidi: nitrogen

Teacher: that's my boy!!!

Kemi: hydrogen

Techer: wonderful!

Apkos: Tear gas

Teacher: Apkos, you have one more chance, else you will be punished

Apkos thinks hard and says: Fabregas.