The oxidation is occurring on Calcium ions as it release one electron and reduction will be occurring on fluorine ion as it accepts one electron.
<u>Explanation:</u>
An element will undergo oxidation and form a positive ion on releasing one or more electrons from its valence shell. While reduction is occurred in a chemical reaction, then the element will be forming a negative ion with the acceptance of one or more electrons in its valence shell.
So in the given process of calcium fluoride, the one electron from the valence shell of calcium will be released making it as 
ions and this is termed as oxidation process. This one electron will be getting accepted by the fluorine ion and thus it will convert to 
ions. This process of acceptance of electrons is termed as reduction.
Somethings that are beneficial is its good for plants, if it is very fine ash it is able to break down and quickly dissolve into the soil.
Answer:
First, let's express pressure P in Pa and volume V in m3:
⇒P=175 kPa
⇒P=1.75×105 Pa
and
⇒V=275 ml
⇒V=2.75×10−4 m3
Then, let's solve the ideal gas law PV=nRT for temperature T:
⇒PV=nRT
⇒T=PVnR
Substituting the appropriate values into the equation:
⇒T=1.75×105×2.75×10−40.80×8.314 K
⇒T=48.1256.6512 K
∴T≈7.24 K
Therefore, the temperature is around 7.24 K.
