Answer:
the velocity is 25 m/s
Explanation:
The computation of the velocity is shown below:
As we know that
Magnitude of Momentum = (mass) × (speed)
75 kg. m/s = 3 kg × speed
So, the speed is
= 75 ÷ 3
= 25 m/s
hence, the velocity is 25 m/s
Answer:

Explanation:
You can calculate the entropy change of a reaction by using the standard molar entropies of reactants and products.
The formula is

The equation for the reaction is
C₂H₄(g) + 3O₂(g) ⟶ 2CO₂(g) + 2H₂O(ℓ)
ΔS°/J·K⁻¹mol⁻¹ 219.5 205.0 213.6 69.9

13 because an atom has the same number of protons as neutrons
Sodium-22 remain : 1.13 g
<h3>Further explanation
</h3>
The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually, radioactive elements have an unstable atomic nucleus.
General formulas used in decay:

T = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
half-life = t 1/2=2.6 years
T=15.6 years
No=72.5 g

It is a combustion reaction because when methane burns with oxyzen it produces carbon dioxide,water and heat and light.