Explanation:
Hi for this one u just need to remember and use the equation.

then u find mr of potassium which is 39.1.
then u do

you get the answer as 0.5115 write ur answer to 3 significant figures which will be 0.512 moles .
hope this helps :)
<u>Answer</u>:
A solid will melt at the temperature at which the kinetic energy breaks the
inter-molecular attractions.
<u>Explanation</u>:
The melting point is the state at which "a substance changes its temperature from a solid to liquid". At the melting point temperature, there is an equilibrium between the both the solid and the liquid phase. When the solid particle is heated by increasing the temperature the particle in the solid vibrate quickly and it absorbs kinetic energy.
It leads to the breaking of the organisation of particle in between the solid and that leads to the melting of solid. Thus, at the melting point, the kinetic energy breaks the inter-molecular attractions.
<u>Answer:</u> The speed of light in miles per minutes is 
<u>Explanation:</u>
We are given the speed of light is
and we need to convert it into miles/min. So, we use the converion factor:
1 hour = 60 minutes
Converting that quantity into miles/minutes, we get:

Hence, the speed of light in miles per minutes is 