A. When the substance is in its gaseous state.
<u>Explanation:</u>
When a substance is expanding against its constant volume and pressure, its temperature increases except when the substance is in gaseous state and not in liquid or solid state. So the internal energy increase in the system not only increases and maintaining the volume and pressure of the system remains constant in its gaseous phase. In the first law of Thermodynamics, it is used specifically that to especially in the case of gaseous system.
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C ........................
Answer:
249.94ppm
Explanation:
Given parameters:
Mass of Pb(NO₃)₂ = 0.025g
Mass of water = 100g
Unknown:
Concentration of solution in ppm = ?
Solution:
Concentration in parts per million gives the amount of solute found in a million units of the solution. They are desirable for expressing very small amount of solutes in a large solution. For example, the level of arsenic in the soil.
Concentration in ppm = 
A solution is made up of solute and solvent. The solvent here is water.
mass of solution = mass of solute + mass of solvent = 0.025 + 100 = 100.025g
Concentration in ppm =
= 249.94ppm
Answer:
no
Explanation:
there is not room for atoms and no atoms = no energy ,no energy = no friction.i am sorry if you are confused