Ummmmmmm......... im in 6th grade and i do not understand 1 bit of this, but i tried, sorry! :)
Answer:
78% nitrogen, 21% oxygen and about 1 percent argon
Explanation:
If we're talking about the element Magnesium, it'd be in period three.
Mass of 1 centigram is equal to 0.01 grams
So, option C is your answer!
Hope this helps!
Currently in this equation, you have 2 hydrogen atoms and 2 oxygen atoms on the left, and then 2 hydrogen atoms and 1 oxygen atom on the right. To balance, you would need to even out the oxygens, so we can first place a 2 in front of H2O to get:
H2 + O2 -> 2H2O
Now, however, you can see that we have too many hydrogen atoms on the right, so to get the final answer, we add a 2 in front of hydrogen on the left:
2H2 + O2 -> 2H2O
I hope this helps!
