Newland's law of octave applies to which of the following set elements ?

Options

A. `Be, Mg, Ca`
B. `As, K, Ca`
C. `B, N, C`
D. None of these

Explanation

To determine which set of elements Newland's law of octaves applies to, we need to follow these steps:

### Step 1: Understand Newland's Law of Octaves
Newland's law of octaves states that when elements are arranged in order of increasing atomic weight, every eighth element has similar properties. This means that if we take any element, the element that is seven places away from it in the list will have similar physical and chemical properties.

### Step 2: Identify the Elements
We will analyze the provided sets of elements:
1. Beryllium (Be), Magnesium (Mg), Calcium (Ca)
2. Arsenic (As), Potassium (K), Calcium (Ca)
3. Boron (B), Nitrogen (N), Oxygen (O)
4. Lithium (Li), Sodium (Na), Potassium (K)

### Step 3: Analyze Each Set
- **Set 1: Beryllium, Magnesium, Calcium**
- Beryllium (Be) is the first element.
- Counting seven elements from Beryllium:
- Be (1), B (2), C (3), N (4), O (5), F (6), Ne (7) - skip Ne (noble gas)
- Next element after seven is Sodium (Na) (8).
- Counting from Magnesium (Mg):
- Mg (1), Al (2), Si (3), P (4), S (5), Cl (6), Ar (7) - skip Ar (noble gas)
- Next element after seven is Potassium (K) (8).
- Therefore, Beryllium, Magnesium, and Calcium do follow the law.

- **Set 2: Arsenic, Potassium, Calcium**
- Arsenic (As) is not seven places away from Potassium (K) or Calcium (Ca).
- This set does not follow the law.

- **Set 3: Boron, Nitrogen, Oxygen**
- Boron (B) to Nitrogen (N) is only two places apart.
- This set does not follow the law.

- **Set 4: Lithium, Sodium, Potassium**
- Lithium (Li) to Sodium (Na) is one place apart, and Sodium to Potassium (K) is also one place apart.
- This set does not follow the law.

### Step 4: Conclusion
The only set that follows Newland's law of octaves is **Beryllium, Magnesium, and Calcium**.

### Final Answer
The correct set of elements to which Newland's law of octaves applies is **Beryllium, Magnesium, and Calcium**.

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