Answer: The new penny is not pure copper
Explanation:
Density
is defined as a relation between the mass
and the volume
:

Now, we are told the density of pure copper is:

And we are given the mass and volume of the new penny, with which we can calculate its density:

As we can see the density of this penny is not equal to the density of pure copper, hence the new penny is not pure copper.
The correct answer is D hydrogen and chlorine need to be balanced there's an equal amount of magnesium on each side. I just took the test and got the correct answer.
Answer:
There is 3 sulfur and 12 oxygen atoms
<span>Evaporation from the oceans is the primary mechanism supporting the surface-to-atmosphere portion of the water cycle</span>
Answer:
NH₄CN, NH₄IO₃, Fe(CN)₃, Fe(IO₃)₃
Explanation:
Cations (positively charged ions) can only form ionic bonds with anions (negatively charged ions). However, you can't just simply put one cation and one anion together to form a compound. Each compound needs to been neutral, or have an overall charge of 0. When cations and anions do not have charges that perfectly cancel, you need to modify the amount of each ion in the compound.
1.) NH₄CN
-----> NH₄⁺ and CN⁻
-----> +1 + (-1) = 0
2.) NH₄IO₃
-----> NH₄⁺ and IO₃⁻
-----> +1 + (-1) = 0
3.) Fe(CN)₃
-----> Fe³⁺ and CN⁻
-----> +3 + (-1) + (-1) + (-1) = 0
4.) Fe(IO₃)₃
-----> Fe³⁺ and IO₃⁻
-----> +3 + (-1) + (-1) + (-1) = 0