Question

What is meant by the law of conservation of energy?
A:
2. What is the difference between an endothermic and exothermic reaction? A:
3. Energy acts at two different scales. What are they?A:
4. What is thermal energy? A:
Forms of Energy at two scales
5. What are electron energy levels? A:
6. Compare the potential energy of an electron closer to the nucleus compared to farther away from the nucleus. A:
7. Explain how neon lights work at a molecular level. A:
8. What is a flame test? A:

one sentences

Answer 1

1. Law of conservation of energy: Energy cannot be created or destroyed, only converted from one form to another, so the total energy of an isolated system remains constant.

2. Endothermic vs exothermic: Endothermic reactions absorb heat from the surroundings, while exothermic reactions release heat to the surroundings.

3. Two scales of energy: Macroscopic (bulk/observable forms like mechanical or thermal energy) and microscopic (atomic, molecular, and electronic energy).

4. Thermal energy: Thermal energy is the total kinetic energy of the microscopic particles in a substance related to its temperature.

5. Electron energy levels: Electron energy levels are quantized states or shells that electrons can occupy in an atom or molecule, each with a specific energy.

6. Electron potential energy vs distance: An electron closer to the nucleus has lower (more negative) potential energy due to stronger electrostatic attraction, while one farther away has higher (less negative) potential energy.

7. How neon lights work: Applying a voltage through neon gas excites electrons to higher energy levels, and when they relax back down they emit photons of characteristic orange-red wavelengths.

8. Flame test: A flame test identifies metal ions by the characteristic color produced when heat excites their electrons and they emit specific wavelengths as they return to lower energy levels.