The Periodic Table Practice Questions

State what the atomic number of an element tells you about an atom of that element.

Using the table, give the symbols of two elements that are non-metals.

Write the electronic configuration of an atom of aluminium in the form 2.8.1

Which row describes the order Mendeleev used to arrange the elements in his table?

Put a cross ( ☒ ) in the box next to your answer.

	order used
A	increasing atomic number
B	increasing relative atomic mass
C	decreasing relative atomic mass
D	alphabetical order of the element names

Mendeleev left gaps in his periodic table.

Explain why he left these gaps.

The diagram shows the arrangement of the electrons in an atom of boron.

Write the electronic configuration of boron in the form 2.8.1

An element is in group 2 and period 3 of the periodic table.

Give the electronic configuration of an atom of this element.

Draw a diagram to show the arrangement of the electrons in an atom of fluorine (atomic number 9).

Explain how Mendeleev was able to predict the properties of eka-aluminium before it had been discovered.

Explain why the discovery of gallium made other scientists more confident that Mendeleev's periodic table was correct.

Explain why Mendeleev placed tellurium before iodine, even though this did not follow his order of increasing relative atomic mass.

Explain why tellurium is still placed before iodine in the modern periodic table, and why tellurium has the greater relative atomic mass.

State where non-metals are found in the periodic table.

Explain, in terms of electrons, why magnesium is a metal and sulfur is a non-metal.

Compare the way Mendeleev arranged the elements in his periodic table with the way the elements are arranged in the modern periodic table.

In your answer you should explain why the modern arrangement puts some pairs of elements in a different order from the order of their relative atomic masses.