There are 20.5 x 10^24 molecules are present in 3.4 moles of NH4NO3.
<h3>How many molecules in 3.4 moles of NH4NO3?</h3>
We know that one mole of a substance has 6.022 × 10²³ molecules so in 3.4 moles of NH4NO3, we have 20.5 x 10^24 molecules if we multiply the 6.022 × 10²³ with 3.4.
So we can conclude that there are 20.5 x 10^24 molecules are present in 3.4 moles of NH4NO3.
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Answer:
is the isotopic notation of the atom
Explanation:
The isotope notation is:

<em>Where a is the mass number = Number of protons + Number of neutrons</em>
<em>b is atomic number = Number of protons</em>
The atomic number define the nature of the atom, the element with atomic number = 15 is phosphorus, P:

a = 15 protons + 16 neutrons = 31
b = 15
is the isotopic notation of the atom.
Neutrons were discovered by James Chadwick<span> in 1932, when he demonstrated that penetrating radiation incorporated beams of neutral particles. Neutrons are located in the nucleus with the protons. Along with protons, they make up almost all of the mass of the </span>atom<span>.
Hope this helps. </span>
Answer : The time required for decay is, 84 days.
Explanation :
Half-life of chromium-51 = 28 days
First we have to calculate the rate constant, we use the formula :



Now we have to calculate the time required for decay.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = time taken by sample = ?
a = let initial activity of the sample = 100
a - x = amount left after decay process = 12.5
Now put all the given values in above equation, we get


Therefore, the time required for decay is, 84 days.
The total pressure when the new equilibrium is stabilized is half of the initial pressure of the system.
The given chemical reaction at a stable equilibrium is,
2H₂O(g)+O₂(g) = 2H₂O₂(g)
According to the ideal gas equation,
PV = nRT
P is pressure,
V is volume,
n is moles
R is gas constant,
T is temperature.
Assuming the temperature is constant.
If the volume of the system is twice the initial volume then the total pressure at the new equilibrium can be found out as,
P₁V₁ = P₂V₂
Where, P₁ and V₁ are initial volume and pressure while P₂ and V₂ are final pressure and volume.
If V₂ = 2V₁,
P₂ = P₁/2
So, the final total pressure will be half of the initial pressure.
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