Answer: the atomic number 7 is
Nitrogen
Explanation:
The answer to the question is 300meters.
The redox reaction is

Here
Calcium undergoes reduction, and acts as cathode
Lithium undergoes oxidation and acts as anode
The reduction potential of calcium is -2.87 V
The reduction potential of lithium is - -3.05 V
We know that
Ecell = Ecathode - Eanode
Ecell = -2.87 - (-3.05) = 0.18 V
The volume increases when the balloon temperature increases.
<u>Explanation:</u>
-10 F is converted into Kelvin as 249 K.
0°C is nothing but 0+ 273 = 273 K
And the room temperature is 25°C which is converted into Kelvin as 273 + 25 = 298 K.
249 K is below room temperature.
As per the Charles' law volume and temperature are directly proportional to each other, when the pressure of the gas remains constant.
V ∝ T
As the balloon temperature increases, the volume also increases.