Science — CBSE Class 10 board question

The table is associated with Newlands' Law of Octaves.

Two Important Features:

1. When elements are arranged in increasing order of atomic masses, every eighth element has properties similar to the first, like the eighth note of a musical scale (octave).
2. It was the first attempt to classify elements systematically, covering elements from hydrogen (H) to thorium (Th).

Two Anomalies:

1. It worked only up to calcium; after calcium, every eighth element did not possess properties similar to the first element.
2. Newlands adjusted two elements in one slot (e.g., Co and Ni, Ce and La) to fit the pattern, which was not justified.

The musical note pattern in the table is the direct clue — Newlands compared element repetition to musical octaves. Examiners expect you to name the law clearly, then give exactly two features and two anomalies (each as a distinct point). Common mistakes: confusing this with Mendeleev's law, or giving only one anomaly. Stick to the points above for full marks.