Answer:
a)The total number of platinum atoms are
.
b)The radius of a Pt atom is 138.7 pm.
Explanation:
a) Let the total number of platinum atoms be x
And mass of x atoms of platinum be m
Edge length of platinum cube ,s= 1.0 cm
Volume of the cube = 
Density of the platinum cube = 
Mass = Density × Volume

Mass of an atom of platinum = 


b) If only 74 percent of the space inside the cube is taken up by Pt atoms.
Volume occupied by platinum atoms = 74% of 

Volume occupied by
atoms is
.



The radius of a Pt atom is 138.7 pm.
Marine regression means that, submerged sea floor are exposed. It exposes the sea bottom while the transgression may result into flooding. A sea level transgression or marine transgression means when the water level or sea level arises in land, it also means that the sea level will move towards higher land.
The product formed when Ag2O decompose is O2 ( answer c)
explanation
Decomposition involve separation of a single chemical compound into two ore more elemental parts Ag2O decomposes to yield Ag and O2
that is 2Ag2O→ 4Ag + O2
2 moles of Ag2O decomposes to yield 4 moles of Ag and 1 mole of O2
Answer:
The volume is
<h2>180 mL</h2>
Explanation:
In order to solve for the volume we use the formula for Boyle's law which is
<h3>

</h3>
where
P1 is the initial pressure
V1 is the initial volume
P2 is the final pressure
V2 is the final volume
Since we are finding the final volume we are finding V2
Making V2 the subject we have
<h3>

</h3>
From the question
P1 = 300 mmHg
V1 = 300 mL
P2 = 500 mmHg
Substitute the values into the above formula and solve for the final volume obtained
That's
<h3>

</h3>
We have the final answer as
<h3>180 mL</h3>
Hope this helps you
Atoms that carry an electric charge because they gained or lost electrons are called ions.