Answer:The statement 'atoms gain energy during evaporation and boiling' BEST describes the energy changes associated with evaporation and boiling.
In a given substance (e.g., water), atoms gain energy when they obtain kinetic energy, i.e. when they gain movement.
Evaporation refers to the physical process where a liquid is converted to a gas (in this case, water).
These processes (evaporation and boiling) increase the kinetic energy of water molecules to the detriment of the potential energy.
In conclusion, the statement 'atoms gain energy during evaporation and boiling' BEST describes the energy changes associated with evaporation and boiling.
Answer:
M₂ = 1.9 M
Explanation:
Given data;
Volume of sodium chloride = 200 mL
Molarity of sodium chloride = 4.98 M
Volume of water = 532 mL
Final Molarity = ?
Solution:
M₁V₁ = M₂V₂
M₂ = M₁V₁ /V₂
M₂ = 4.98 M × 200 mL / 532 mL
M₂ = 996 mL. M /532 mL
M₂ = 1.9 M
Answer: 7
Explanation: oxygen has 5 atoms and nitrogen has 2. Put them together and you get 7