Answer:
A.
Explanation:
A decomposition reaction is when one reactant (the substances to the left of the arrow in the reaction) breaks apart into two or more products (the substances to the right of the arrow).
Because KClO3 is breaking down into KCl and O2, it's a decomposition reaction.
For the first one I think it’s A, and I think the second one is C. Those seem most logical.
Answer:
<h2>1.2 g/mL</h2>
Explanation:
The density of a substance can be found by using the formula

From the question
mass = 30 g
volume= 25 mL
We have

We have the final answer as
<h3>1.2 g/mL</h3>
Hope this helps you
Answer:
Helium is lighter than Hydrogen and Helium is a much safer gas.