<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
Scientists use the physical and chemical properties to help them identify and classify matter. These physical and chemical properties are in a macro-perspective, in which these matter contains compounds, elements and atoms. Hence, matter can be classified in various ways, <span><span>
1. </span>Atomic number either atomic mass each element has</span>
<span><span>2. </span>By substance of that matter either pure substance or mixed substance</span> <span>
3. If they cannot reduce a certain substance into a much smaller quantified atomic structure then they they’ll use (2) to identify and classify it.</span>
You should always do A. form a hypothesis before performing an experiment also the other options cannot happen until after an experiment.
D. melting ice on roads and sidewalks, i think
2KClO3 --> 2KCl + 3O2
3 moles of oxygen are produced when 2 mol of potassium chlorate (KClO3) decompose.
