The first law of thermodynamics is represented by the equation:

Options

A. `DeltaE= Q- W`
B. `DeltaE= Q+W`
C. `W= Q + DeltaE`
D. `Q= W+ DeltaE`

Explanation

**Step-by-Step Solution:**

1. **Understanding the First Law of Thermodynamics**:
The first law of thermodynamics is essentially a statement about the conservation of energy. It states that energy cannot be created or destroyed, but can only be transformed from one form to another.

2. **Mathematical Representation**:
The first law can be mathematically expressed as:
\[ \Delta U = Q + W \]
where:
- \(\Delta U\) is the change in internal energy of the system.
- \(Q\) is the heat added to the system.
- \(W\) is the work done on the system.

3. **Interpreting the Terms**:
- **Internal Energy (\(\Delta U\))**: This represents the total energy contained within the system, which depends on the state of the particles in the system.
- **Heat (Q)**: This is the energy transferred due to temperature difference. If heat is added to the system, \(Q\) is positive; if heat is lost, \(Q\) is negative.
- **Work (W)**: This is the energy transferred when a force is applied over a distance. If work is done on the system, \(W\) is positive; if work is done by the system, \(W\) is negative.

4. **Examples of the First Law**:
- **Light Bulb**: A light bulb converts electrical energy into light and heat energy. The total energy remains constant, just transformed into different forms.
- **Gas Stove**: A gas stove converts chemical energy from natural gas into heat energy for cooking.

5. **Conclusion**:
The first law of thermodynamics emphasizes that the total energy in an isolated system remains constant, and it can be expressed using the equation \(\Delta U = Q + W\).