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New
New
Year 10
Edexcel
Foundation

Development of the periodic table

I can describe the development of the periodic table and explain its current form.

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Share activities with pupils
New
New
Year 10
Edexcel
Foundation

Development of the periodic table

I can describe the development of the periodic table and explain its current form.

Download all resources
Share activities with pupils

Lesson details

Key learning points

  1. Dalton (1803) arranged known elements in order of atomic weights.
  2. Newlands (1865) noticed that every eighth element, in order of atomic mass, repeated similar properties.
  3. Mendeleev swapped the order of atomic weights in order to fit elements better into groups of similar properties.
  4. Mendeleev’s periodic table had gaps and he predicted missing elements that were later found.
  5. Mendeleev was not aware of isotopes, so was unable to explain why the ordering by atomic weight was not always correct.

Common misconception

Pupils often believe that the when the periodic table was devised, scientists knew about the subatomic particles.

Emphasise when the subatomic particles were discovered in comparison to when Mendeleev devised his periodic table.

Keywords

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

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

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

  • Dmitri Mendeleev - A scientist who devised the periodic table of elements.

The use of timelines can help here and give the pupils activities to compare the similarities and differences between Newland's, Mendeleev's and the modern periodic tables.
Teacher tip

Equipment

It is useful for students to have a copy of the periodic table.

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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Starter quiz

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6 Questions

Q1.
How many elements are shown in the periodic table? Give your answer in numerical digits (e.g. 10).
Correct Answer: 118, one hundred and eighteen
Q2.
Match the definitions for 'group' and 'period,' and then match the named elements to their respective group or period numbers.
Correct Answer:group,vertical column in the periodic table

vertical column in the periodic table

Correct Answer:period,horizontal row in the periodic table

horizontal row in the periodic table

Correct Answer:neon,period 2

period 2

Correct Answer:potassium ,Group 1

Group 1

Correct Answer:alumnium,period 3

period 3

Correct Answer:chlorine,Group 7

Group 7

Q3.
Which of the following information is shown for each element on the periodic table?
Correct answer: atomic symbol
boiling point
Correct answer: atomic (proton) number
density
Correct answer: relative atomic mass
Q4.
Put the following elements in order of increasing atomic number, starting with the smallest.
1 - boron
2 - magnesium
3 - sulfur
4 - copper
5 - tin
6 - tungsten
7 - francium
Q5.
Which of the following are properties of a substance?
Correct answer: atomic mass
Correct answer: atomic (proton) number
Correct answer: melting point
Correct answer: number of electrons
Correct answer: conductor of electricity or heat
Q6.
Match the following elements to the correct information.
Correct Answer:sodium,11 protons, 11 electrons and 12 neutrons

11 protons, 11 electrons and 12 neutrons

Correct Answer:arsenic,33 protons, 33 electrons and 42 neutrons

33 protons, 33 electrons and 42 neutrons

Correct Answer:calcium,Group 2 and period 4

Group 2 and period 4

Correct Answer:barium,period 6 and Group 2

period 6 and Group 2

Correct Answer:silicon,period 3 and Group 4

period 3 and Group 4

Correct Answer:argon,Group 0 and period 3

Group 0 and period 3

Exit quiz

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6 Questions

Q1.
Which of the following scientists is credited with the development of the modern periodic table?
Newton
Dalton
de Chancourtois
Correct answer: Mendeleev
Einstein
Q2.
True or false? The elements in the modern periodic table are arranged according to their atomic number and electronic structures.
Correct answer: true
false
Q3.
Which of the following was the significant observation made by John Newlands regarding the periodicity of elements?
Elements with similar properties repeated every 5th element.
Elements with similar properties appeared in threes or triads.
Elements repeated in a telluric spiral.
Correct answer: Elements with similar properties repeated every 8th element.
Q4.
Match up Newland's actions to their outcome to explain why his periodic table was not accepted by the scientific community.
Correct Answer:repeated a pattern every 8th element,only some similar elements were grouped together e.g. Li, Na and K

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

Correct Answer:did not leave gaps,assumed all elements had been discovered

assumed all elements had been discovered

Correct Answer:ordered elements by atomic weight,dissimilar elements were grouped together e.g. O, S and Fe

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

Correct Answer:put two elements in the same position,needed to double up elements to fit the repeating pattern

needed to double up elements to fit the repeating pattern

Q5.
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?
Correct answer: He left gaps for elements yet to be discovered.
Correct answer: He predicted the properties of elements yet to be discovered.
He added in the noble gases.
Correct answer: He did not order all elements by atomic weight, e.g. tellurium and iodine.
Correct answer: He ordered elements using both the atomic weight and their properties.
Q6.
Order the following scientists and their methods for organising elements in the periodic table, starting with the earliest and ending with the most recent.
1 - Dalton - arranged elements by atomic weight only.
2 - Doberiner - arranged elements by atomic weight in groups of 3, called triads.
3 - de Chancourtois - arranged elements by atomic weight in a telluric spiral.
4 - Newlands - arranged elements by atomic weight and repeated every 8th.
5 - Mendeleev - arranged elements by atomic weight and properties but left gaps.