Question

Given below are a few elements arranged in the order of increasing atomic masses.
If every eighth element had properties similar to that of the first, according to Newlands’ Law of Octaves, identify such pairs. (Note: At that time, noble gases were not discovered.)
| Li | Be | B | C | N | O | F | Na | Mg | Al | Si | P | S |

• A. O, P
• B. C, Si
• C. N, Si
• D. Be, Na

Answer 1

The correct option is B C, Si

According to Newland’s Law of Octaves, the then known elements when arranged in the increasing order of their atomic masses, it is found that every eighth element had properties similar to that of the first. In Newlands' Octaves, the properties of lithium and sodium were found to be same. Sodium is the eighth element after lithium. Similarly, carbon and silicon resemble each other.