Answer:
Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form.
Explanation:
Chemical change involves formation of new substances. Therefore, the correct answer is "Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form."
Answer:
<h2>The answer is 9 g/cm³</h2>
Explanation:
The density of a substance can be found by using the formula

From the question
mass = 216 g
volume = 24 cm³
The density is

We have the final answer as
<h3>9 g/cm³</h3>
Hope this helps you
Answer:
5 g of H₂ are contained in the vessel
Explanation:
A typical excersise of conversion:
We determine molar mass of H₂.
This is a dyatomic molecule, as molar mass of H is 1g/mol, molar mass of H₂ will be 2g/mol.
Let's make the conversion of units:
2.5 mol . 2g/mol = 5 g
5 g of H₂ are contained in the vessel