Answer:
A medium.
<h3>Explanation:</h3>
It's the material the wave is travelling through.
The atomic number is the number of protons in the nucleus of an atom. The number of protons define the identity of an element (i.e., an element with 6 protons is a carbon atom, no matter how many neutrons may be present).
5. B air is a mixture of many elements, but is not a chemically fused.
6. B Beef stew, composition varies throughout.
7. A. They can be chemically separated into their component elements, but they are all homogenous, and as such, have constant composition, which differs from the components properties, as the components must undergo a chemical change to become compounds.
Answer:
<h3>The answer is 7.42 </h3>
Explanation:
The pH of a solution can be found by using the formula
![pH = - log [ { H_3O}^{+}]](https://tex.z-dn.net/?f=pH%20%3D%20-%20log%20%5B%20%7B%20H_3O%7D%5E%7B%2B%7D%5D)
From the question we have

We have the final answer as
<h3>7.42 </h3>
Hope this helps you
Answer:
(b) Both have the same number of valence electrons.
Step-by-step explanation:
We find the most striking chemical similarities between two Main Group elements when they are in the same Group of the Periodic Table.
Elements in the same Group have the same number of valence electrons.
(a) is <em>wrong</em>, because elements in the same group have <em>different masses</em>.
(c) is <em>wrong,</em> because atoms with the same number of protons belong to the s<em>ame element</em>.
(d) is wrong, because elements in the same Group must be in .
<em>different Periods.</em>