Answer : The temperature in degree Celsius is, 
Explanation :
The conversion used for the temperature from Kelvin to degree Celsius is:

where,
= temperature in Kelvin
= temperature in centigrade
As we are given the temperature in Kelvin is, 2.7
Now we have to determine the temperature in Kelvin.



Therefore, the temperature in degree Celsius is, 
The formula mass of a molecule is the sum of the atomic weights of the atoms in the empirical formula of the compound. It is also known as Formula Weight.
The atomic weights of
N = 14.01 amu
H = 1.00 amu
P = 30.97 amu
O = 16.0 amu
Now, we will calculate now the formula mass of a given substance
3(14.01) + 12(1.00) + 1(30.97) + 4(16.0) = 42.03 + 12.00 + 30.97 + 64.0 = 149.0 amu
Therefore, the formula mass for (NH4)3PO4 is 149.0 amu
Overuse of the same chemicals can result in the pest becoming immune to the pesticides.
Since it is in period five, any element that has a higher atomic number than it could be an answer, therefore, silver, bismuth, and osmium are possibilities.