Answer:
8.8 yards per second
Explanation:
50 - 20 = 30 yards
30 yards/3.4 seconds = 8.8235
Pure substances can or can not be chemically combined.
Pure substances can be either elements or compounds, but not mixture. Mixture are different substances mixing together without being chemically combined, such as air, which is a mixture of oxygen, carbon dioxide, water etc. Mixture can be separated by physical methods, like filtration or decantation.
Meanwhile, elements are the substances that cannot be further separated by any means. No matter physical or chemical methods. Examples of elements are oxygen, hydrogen, neon and all the other ones from the periodic table. Compounds are basically elements joining together, but they’re chemically combined which means their electrons (kind of subatomic particle) are either shared or given away. These elements can only be separated by chemical methods like electrolysis or heating.
Therefore, as long as the substance cannot be separated by physical methods, it can be considered as a pure substance. We can now conclude that pure substance can be (element) or can not be (compound) chemically combined.
Answer:
<h3>The answer is 0.75 g/mL</h3>
Explanation:
The density of a substance can be found by using the formula

From the question
mass = 90 g
volume = 120 mL
We have

We have the final answer as
<h3>0.75 g/mL</h3>
Hope this helps you
Answer:
There are multiple ways to check mass but I'll tell you one. Look below
Explanation:
One easy way of checking atomic mass is by adding protons and neutrons.
For example:
We have 5 protons and 4 neutrons.
5+4=9
I hope this helps (: