answer: 3.40625 moles
Explanation: see the attached pics
<span>1.11 g/cm³
Hope this helps! </span>
Answer : The speed in miles per hour is 22 mile/hr.
The speed in yard per min is 26617.8 yard/min
Explanation :
The conversion used for meters to miles is:

The conversion used for second to hour is:

The conversion used for meter per second to mile per hour is:

As we are given the speed of 407.0 meter per second. Now we have to determine the speed in miles per hour.

So, 
Therefore, the speed in miles per hour is 22 mile/hr.
The conversion used for meter to yard
1m = 1.09 yard
The conversion used for second to hour is:

The conversion used for meter per second to mile per hour is:


As we are given the speed of 407.0 meter per second. Now we have to determine the speed in yards per min

So, 
Therefore, the speed in yard per min is 26617.8 yard/min
answer: it is true because a hypothesis is something you think will happen during a experiment
explained: I took the test
The correct description for an atom of helium would be option C. An atom of helium has its valence electrons in its first energy level, it wouldn't and can't satisfy the Octet rule as it only has 2 electrons, but with 2, it has a full shell, as the first energy level can hold only 2 electrons.