Practice Questions Periodic Table

What is the name of the scientist who first proposed the Law of Octaves?

• Mendeleev

• Moseley

• Newlands

• Dalton

What does the atomic number of an element represent?

• The number of neutrons

• The number of protons

• The number of valence electrons

• The atomic mass

Which term describes a horizontal row in the periodic table?

• Group

• Family

• Period

• Block

Which scientist discovered that elements should be arranged by atomic number instead of atomic mass?

• Newlands

• Mendeleev

• Moseley

• Bohr

Which subatomic particle plays the biggest role in determining an element’s chemical properties?

• Proton

• Neutron

• Electron

• Nucleus

What problem did Mendeleev encounter when organizing elements by atomic mass?

• Some elements seemed out of order based on their properties.

• He did not know about electrons.

• The noble gases had not been discovered yet.

• He included too many elements.

Why do elements in the same group have similar properties?

• They have the same atomic number.

• They have the same number of valence electrons.

• They have the same mass number.

• They are all metals.

How did Mendeleev’s table allow scientists to predict undiscovered elements?

• He used trends in atomic number.

• He used patterns in element properties.

• He guessed based on element color.

• He assigned random properties to missing elements.

What distinguishes the modern periodic table from earlier versions?

• It has fewer elements.

• It arranges elements by atomic number instead of atomic mass.

• It no longer groups elements with similar properties.

• It does not include transition metals.

Why do d-block elements have more complex electron configurations than s- and p-block elements?

• They have larger atomic radii.

• The d-electrons do not fill orbitals sequentially.

• They are gases at room temperature.

• They have no valence electrons.