The light radiations with discrete quantities of energies are called............

Answer

To solve the question, "The light radiations with discrete quantities of energies are called............", we can follow these steps:

### Step 1: Understand the Concept of Energy in Light
Light is a form of electromagnetic radiation, and according to quantum theory, energy is not emitted or absorbed continuously. Instead, it is emitted in discrete amounts.

**Hint:** Recall that energy can be quantized, meaning it comes in specific, fixed amounts rather than a continuous range.

### Step 2: Introduce Planck's Quantum Theory
Max Planck proposed that energy is emitted in small packets called "quanta." This theory laid the foundation for quantum mechanics and explains how energy levels are quantized.

**Hint:** Think about the historical context of quantum theory and how it changed our understanding of energy.

### Step 3: Define the Term "Quantum"
The term "quantum" refers to the smallest discrete quantity of energy. In the context of light, these quanta are specifically related to electromagnetic radiation.

**Hint:** Remember that "quantum" is a general term for discrete energy packets, applicable to various forms of energy.

### Step 4: Specify the Term for Light
For light, the discrete packets of energy are specifically called "photons." A photon is the fundamental particle of light, carrying energy and momentum.

**Hint:** Consider the relationship between light and its particle-like properties, which leads to the concept of photons.

### Step 5: Complete the Sentence
Based on the understanding that light radiations with discrete quantities of energy are called photons, we can fill in the blank.

**Final Answer:** The light radiations with discrete quantities of energies are called **photons**.

### Summary
1. Energy in light is quantized.
2. Planck's theory introduced the concept of quanta.
3. The term "quantum" refers to discrete energy packets.
4. For light, these packets are called "photons."
5. Therefore, the answer is **photons**.