Do you know what is meant by needed? does it mean lone pairs?
What you were given is the balanced chemical equation
Answer:
A variable shape that adapts to fit its container.
<h2>
Answer:</h2>
7 hydrogen atoms
<h2>
Explanation:</h2>
N<em><u>H4</u></em>C2<em><u>H3</u></em>02
In this problem we see the hydrogen atom twice, along with the numbers 4 and 3 next to them. (as shown above in bold & underlined)
So, in order to find how many there are in all you add both hydrogen atoms together-
H4+H3= H7
therefore, there are 7 hydrogen atoms in all