Answer:
a)
and 
b)
and 
c)
and 
Explanation:
Temperature of the gas is defined as the degree of hotness or coldness of a body. It is expressed in units like
,
and
These units of temperature are inter convertible.



a) 68°F (a pleasant spring day) to °C and K.
Converting this unit of temperature into
and
by using conversion factor:



b) 164°C (the boiling point of methane, the main component of natural gas) to K and °F
Conversion from degree Celsius to Kelvins and Fahrenheit



c) 0K (absolute zero, theoretically the coldest possible temperature) to °C and °F.




Number of atoms : 1.26 x 10²³
<h3>Further explanation </h3>
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
0.21 moles of Al, so n = 0.21
Number of atoms :

Answer is: pH <span>of a 0,01 M solution is 2.
c(HNO</span>₃) = 0,01 M = 0,01 mol/L.
pH = -log(c(HNO₃).
pH = -log(0,01 mol/L).
pH = 2.
pH<span> is a numeric scale used to specify the </span>acidity<span> or </span>basicity<span> of an </span>aqueous solution<span>. If pH is less than seven, than solution is acidic and if pH is greater seven, solution is basic, if pH is equal seven, solution is neutral.</span>
(sample g/1) X (1 mole/40.078(MW of Ca)) = moles of sample (moles of sample)(6.022 x 10^23( no of atoms)/ 1 mole) = # of atoms in a 120 g sample of calcium Avogadro's number=6.022x 10^23 atoms in 1 mole