Answer:
A type of an atom which has a different number of neutrons but the same atomic number, therefore making it the same element. This atom would still have the same properties as well. (Ex: Vanadium-51 is an isotope of Vanadium that has 51 neutrons but still has 23 protons, as its atomic number is 23.)
Answer:

Explanation:
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In this case, since there is a 2:2 mole ratio between sodium peroxide and water according to the given reaction, it is possible to apply the following stoichiometric setup for the calculation of the required mass of water:

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Answer:
n₂ =1.4 mol
Explanation:
Given data:
Mass of nitrogen = 2 g
Initial Volume occupy by nitrogen = 1.25 L
Final volume occupy by nitrogen = 25.0 L
Final number of moles = ?
Solution;
Formula:
V₁ / n₁ = V₂ / n₂
Number of moles of nitrogen:
Number of moles = mass/ molar mass
Number of moles = 2 g/ 28 g/mol
Number of moles = 0.07 mol
Now we will put the values in formula:
V₁ / n₁ = V₂ / n₂
n₂ = V₂× n₁ /V₁
n₂ = 25 L × 0.07 mol / 1.25 L
n₂ = 1.75 L. mol / 1.25 L
n₂ =1.4 mol
Well all reactions need energy to start it. The light is the energy that the reaction requires to start it. Sunlight also has no mass in the first place so laws of conservation of mass don't apply to it.
To balance this equation you would do whatever you did I TO one side to the other... so if there is 18 oxygen on the right side then there must be 18 on the left. So 18/2 equals 9... the. You equation will be balanced