9 g of hydrogen - 42 g of nitrogen
5 g of hydrogen - x g of nitrogen

The mass of nitrogen in the second sample is 23.33 g.
The answer for this question is: Atoms
The volume of H₂ evolved at NTP=0.336 L
<h3>Further explanation</h3>
Reaction
Decomposition of NH₃
2NH₃ ⇒ N₂ + 3H₂
conservation mass : mass reactants=mass product
0.28 NH₃= 0.25 N₂ + 0.03 H₂
2 g H₂ = 22.4 L
so for 0.03 g :

iii. True. The existence of a vacancy in a crystal decreases the energy of the material.
One of the scientific disciplines called crystallography examines how the atoms in a solid crystal are arranged. When molecules are linked together in a regular way, these crystals are created.
The mechanical, physical, and optical properties of a material can alter when crystal flaws are present. The strength of the material can be impacted by a flaw.
An irregularity in the atoms' regular geometrical arrangement within a crystalline material is referred to as a crystal defect. These flaws are caused by the solid being deformed, cooling quickly from a high temperature, or being exposed to high-energy radiation (such as X-rays or neutrons). because the vacancy cause defects and the crystal structure is disturbed this causes a decrease in energy.
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