How do metalloids generally appear in terms of luster?

B. Dull and non-reflective like non-metals

Which of the following best describes elements in terms of their complexity?

A. They are the simplest substances known

B. They are complex mixtures of compounds

C. They are formed by combining two or more atoms of different types

D. They can be broken down into simpler substances by chemical means

Everyday Science · Atoms, Elements & Compounds · page 3 of 3

Includes 3 past paper MCQs (marked).

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21.
Past Paper MCQ
Who arranged the periodic table on the basis of atomic numbers of elements?
Correct Answer: B. Henry Moseley
One-liner
The periodic table was arranged on the basis of atomic numbers by Henry Moseley.
22.
How do metalloids generally appear in terms of luster?
Correct Answer: C. Somewhere in the middle
One-liner
Metalloids generally have a luster that is somewhere in the middle — neither fully shiny like metals nor completely dull like non-metals.
23.
Water is made up of two namely oxygen and hydrogen.
Correct Answer: C. Elements
One-liner
Water is made up of two elements, namely oxygen and hydrogen.
24.
Which of the following best describes elements in terms of their complexity?
Correct Answer: A. They are the simplest substances known
One-liner
Elements are the simplest substances known because they cannot be broken down into simpler substances by ordinary chemical means.
25.
In the periodic table, rows are considered to be ?
Correct Answer: B. Periods
One-liner
In the periodic table, horizontal rows are called periods.
26.
Hydrogen exists as?
Correct Answer: B. Molecules
One-liner
Hydrogen exists as molecules (H₂), meaning two hydrogen atoms bond together to form a diatomic molecule.
27.
Which one of the following elements can exist in a mono-atomic molecular state?
Correct Answer: D. Neon
One-liner
Neon is a noble gas and exists in a mono-atomic (single-atom) molecular state because its valence shell is complete, making it chemically inert.