Nitrogen gas has the chemical formula N2. One molecule of nitrogen gas is made up of two atoms of nitrogen.
The correct option is C.
Explanation:
Nitrogen gas has the chemical formula 
, which means that two atoms of nitrogen element combined to form nitrogen gas.
The combination of two atoms of element nitrogen produce dinitrogen atom.
Dinitrogen is the nitrogen gas usually present in atmosphere of the earth in abundance.
2 atoms of nitrogen element
N + N =
the gas is colorless and odorless formed at standard condition of temperature and pressure. The two nitrogen atoms are tightly bonded with triple bonds in between the atoms.
CO2 is not polar as in this case the same types of molecules
are pulling in the same as well as opposite direction. CH4 is also not polar as
there is no imbalance in the charge of the molecules. CBr4 is also not polar
because in this case also no imbalance in the molecular charges can be seen.
CHBr3 is a bit polar in nature because it has different kind of charges at its
opposite ends. S among the all 4 options CHBr3 is polar.
Answer:
The heat lost by the water 
3.8 KJ
The heat gain by ice 
= 228.76 J
The heat required to melt the ice 
= 3340 J
Explanation:
Mass of ice cube 
= 10 gm
Initial temperature of ice cube 
= 0 °c
Mass of water 
= 100 gm
Initial temperature of water 
= 20 °c
Final temperature of mixture 
= 10.93 °c
(a). Total heat lost by the water 
( - )
⇒ 100 × 4.184 (20 - 10.93)
⇒ 3.8 KJ
This is the heat lost by the water.
(b). Heat gained by the ice cube = 
⇒ = 10 × 2.093 × ( 10.93 - 0)
⇒ = 228.76 J
This is the heat gain by ice.
(C). Heat required to melt the ice = × Latent Heat
⇒ = 10 × 334
⇒ = 3340 J
This is the heat required to melt the ice.
The energy in Joules is calculated as:
E = VQ
At standard conditions, the standard potential or the voltage is equal to 0.76 V. Next, we have to determine Q. The formula is as follows:
Q = nF, where n is the number of moles electron, while F is the Faraday's constant (96,500 C/mol e)
From the given reaction, notice that Zn was converted to Zn²⁺, while Cu²⁺ to Cu. So, 1 mol Cu = 2 mol e.
Q = 51 g Cu (1 mol Cu/63.55 g)(2 mol e/1 mol Cu)(96,500 C/mol e)
Q = 154885.92 C
Thus,
E = (0.76 V)(154885.92 C)
<em>E = 117,713.3 J</em>
We can predict the order of the elements given above according from the highest to lowest first ionization energies by using the trends in a periodic table. For elements in a family, the ionization energy decreases as it goes down. Therefore, the correct order would be Be, Mg, Ca, Sr.
