Question

how was the work of newlands similar to that of mendeleev on the periodic table?
○ they both arranged the elements in order of increasing atomic mass.
○ they both arranged elements that had similar properties into groups.
○ they both predicted the positions of undiscovered elements on the table.
○ they both placed the relative atomic mass of each element on the table.

Explanation:

• Option 1: Newlands arranged elements by atomic mass (law of octaves), Mendeleev also arranged by increasing atomic mass (though he adjusted for properties). But this is a similarity, but let's check others.
• Option 2: Newlands grouped elements with similar properties (octaves, every 8th element), Mendeleev grouped elements with similar properties into groups/periods. However, Newlands' grouping was less accurate (didn't account for transition metals), while Mendeleev's was more refined. But the key similarity in their initial approach was arranging by atomic mass? Wait, no—wait, let's recall: Newlands' law of octaves arranged elements in order of increasing atomic mass, and every 8th element had similar properties. Mendeleev arranged elements in order of increasing atomic mass and grouped similar properties. But the question is about similarity. Wait, the first option: "They both arranged the elements in order of increasing atomic mass." Let's verify: Newlands did arrange by atomic mass (law of octaves, ordered by atomic mass, noticed every 8th element similar). Mendeleev's periodic table was also arranged by increasing atomic mass (he left gaps for undiscovered elements, but the base was atomic mass). The other options:
• Option 2: Newlands' grouping was flawed (didn't work for heavier elements), Mendeleev's grouping was more accurate, but did Newlands "arrange elements that had similar properties into groups"? He noticed the pattern, but his grouping was less systematic.
• Option 3: Newlands did not predict undiscovered elements; Mendeleev did. So this is incorrect.
• Option 4: Did Newlands place relative atomic mass? Maybe, but the key similarity is arranging by atomic mass. Wait, but let's check again. Wait, the correct answer is the first option? Wait, no—wait, maybe I made a mistake. Wait, Newlands and Mendeleev both arranged elements in order of increasing atomic mass. Let's confirm: Newlands' law of octaves: elements in order of atomic mass, every 8th similar. Mendeleev: ordered by atomic mass, grouped similar properties, left gaps. So the first option says "They both arranged the elements in order of increasing atomic mass." That's correct. Let's check the other options:
• Option 2: Newlands' grouping was not as systematic (failed for elements after Ca), while Mendeleev's was. So "arranged elements that had similar properties into groups"—Newlands' approach was more of a pattern (octaves) rather than strict grouping, while Mendeleev grouped. So this is not the best similarity.
• Option 3: Newlands didn't predict undiscovered elements, Mendeleev did. So incorrect.
• Option 4: Not sure if Newlands placed relative atomic mass, but the main similarity is ordering by atomic mass. So the correct option is the first one: "They both arranged the elements in order of increasing atomic mass."

Answer:

A. They both arranged the elements in order of increasing atomic mass.