The very first element similar to lithium according to law of octave is

Options

A. sodium
B. potassium
C. boron
D. neon

Answer

To determine the very first element similar to lithium according to the law of octaves, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Law of Octaves**: The law of octaves was proposed by John Newlands, which states that when elements are arranged in order of increasing atomic mass, every eighth element has similar properties.

2. **List the Elements in Order of Atomic Mass**: We start listing the elements in order of their atomic masses. The first few elements are:
- Hydrogen (H)
- Lithium (Li)
- Beryllium (Be)
- Boron (B)
- Carbon (C)
- Nitrogen (N)
- Oxygen (O)
- Fluorine (F)
- Sodium (Na)

3. **Identify the Position of Lithium**: In the above list, lithium (Li) is the third element.

4. **Count to the Eighth Element**: According to the law of octaves, we count eight elements starting from lithium:
- 1st: Lithium (Li)
- 2nd: Beryllium (Be)
- 3rd: Boron (B)
- 4th: Carbon (C)
- 5th: Nitrogen (N)
- 6th: Oxygen (O)
- 7th: Fluorine (F)
- 8th: Sodium (Na)

5. **Determine the Element Similar to Lithium**: The eighth element after lithium is sodium (Na). According to Newlands' law, lithium and sodium will exhibit similar properties.

### Conclusion:
The very first element similar to lithium according to the law of octaves is **Sodium (Na)**.

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