An atom of an element with the same number of protons, but different mass numbers due to different numbers of neutrons.

The historical name for atomic mass, i.e. the ratio of the mass of an atom compared to a standard.

The mean mass of an atom compared to 1/12 of the mass of a carbon–12 atom.

A scientist who devised the periodic table of elements.

Development of the periodic table

Chemistry

In the Calculations involving mass unit, pupils will learn about calculating the relative formula mass of reactants and products in balanced chemical reactions, and the conservation of atoms and mass, as well as the concept of moles (HT only).

In the Patterns in the periodic table unit, pupils learnt how the chemical and physical properties of different elements are indicated by their position on the periodic table and about key groups of elements. 

Atomic structure and the periodic table

Which of the following scientists is credited with the development of the modern periodic table?

True or false? The elements in the modern periodic table are arranged according to their atomic number and electronic structures.

Elements with similar properties repeated every 5th element.

Elements with similar properties appeared in threes or triads.

Elements with similar properties repeated every 8th element.

Which of the following was the significant observation made by John Newlands regarding the periodicity of elements?

only some similar elements were grouped together e.g. Li, Na and K

dissimilar elements were grouped together e.g. O, S and Fe 

needed to double up elements to fit the repeating pattern 

Match up Newland's actions to their outcome to explain why his periodic table was not accepted by the scientific community. 

He left gaps for elements yet to be discovered.

He predicted the properties of elements yet to be discovered.

He did not order all elements by atomic weight, e.g. tellurium and iodine.

He ordered elements using both the atomic weight and their properties.

Which of the following improvements did Mendeelev make to Newland's periodic table that led to Mendeelev's table being accepted by the scientific community?

Dalton - arranged elements by atomic weight only.

Doberiner - arranged elements by atomic weight in groups of 3, called triads.

de Chancourtois - arranged elements by atomic weight in a telluric spiral.

Newlands - arranged elements by atomic weight and repeated every 8th.

Mendeleev - arranged elements by atomic weight and properties but left gaps.

Order the following scientists and their methods for organising elements in the periodic table, starting with the earliest and ending with the most recent.

How many elements are shown in the periodic table? 
Give your answer in numerical digits (e.g. 10).

Match the definitions for 'group' and 'period,' and then match the named elements to their respective group or period numbers.

Which of the following information is shown for each element on the periodic table?

Put the following elements in order of increasing atomic number, starting with the smallest.

Which of the following are properties of a substance?

Match the following elements to the correct information.

Starter Quiz