Answer: I think it’s B
explanation
Place a burning splint near the opening of a test tube. If a popping noise occurs, it's probably hydrogen. Place a glowing splint in the test tube, and if it reignites, it could be oxygen. Place a burning splint into a test tube, and if it goes out, it could be carbon dioxide.
Answer: 1s2 2s2 2p3
Explanation:
atomic number is 7 hence it shuld be 2,5 if numerically.. tho the standard notation is the above giver answer
Answer:
4
Explanation:
The balanced equation for the reaction is as follows:
4Al + 3O2 --> 2(Al2O3)
I think it's A but it might be different from your school and mine
