In the modern periodic table, elements are arranged in

Options

A. Increasing mass
B. Increasing volume
C. Increasing atomic number
D. Alphabetically

Answer

To solve the question regarding the arrangement of elements in the modern periodic table, we can follow these steps:

### Step 1: Understand the Modern Periodic Law
The modern periodic law states that the properties of elements are a periodic function of their atomic number. This means that when elements are arranged by their atomic number, their chemical properties exhibit a recurring pattern.

**Hint:** Remember that the modern periodic law focuses on atomic number rather than atomic mass.

### Step 2: Identify the Arrangement Criteria
In the modern periodic table, elements are primarily arranged in order of increasing atomic number. This is a key distinction from earlier periodic tables, which were organized by increasing atomic mass.

**Hint:** Look for the term "increasing atomic number" as it is the defining characteristic of the modern periodic table.

### Step 3: Eliminate Incorrect Options
The question provides several options: increasing mass, increasing volume, increasing atomic number, or alphabetically. Since we know that the modern periodic table is based on atomic number, we can eliminate the other options:
- Increasing mass: Incorrect, as the arrangement is not based on mass.
- Increasing volume: Incorrect, as volume is not a criterion for arrangement.
- Alphabetically: Incorrect, as elements are not arranged alphabetically.

**Hint:** Cross out options that do not align with the modern periodic law.

### Step 4: Conclude the Correct Answer
After analyzing the options, we conclude that the correct answer is that elements in the modern periodic table are arranged in increasing atomic number.

**Final Answer:** The correct option is C: increasing atomic number.

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