I am pretty sure the answer is 6.25 molecules
See picture for explanation
Answer:
The answer to your question is: The mass number will be 4 units lower.
Explanation:
Alpha particles are Helium atoms, which have a mass number of 4 and atomic number of 2.
When an alpha particle is released, the original atom loses 2 protons and and 2 neutrons an we can see in the example.
²²⁶ ₈₈ Ra ⇒ ²²² ₈₆ Rn + ⁴₂ He
<span>Raising
the temperature of the reactants increases the reaction between the reactants.
The kinetic energy of the molecules of the reactants collides more frequently
with ach other thereby increasing its reaction. Increasing the concentration of
the reactants increases the reaction rate. Adding a catalyst to the reaction
increases the rate of reaction of a substance. The catalyst hastens the
chemical reaction. </span>
C = 4 mol/l
v = 0.5 l
n(NaCl)=cv
n(NaCl) = 4 mol/l · 0.5 l = 2 mol
2 moles of NaCl must be dissolved