C3 - The Periodic Table Flashcards
How did John Dalton organise the elements?
In order of their masses.
Who made the first suggestion of the periodic table?
John Dalton
How did John Newlands organise the elements?
In order of mass placed in octaves.
Why couldn’t Newlands concept of the periodic table worked?
He assumed all of the elements had been discovered and the pattern broke down after calcium.
How did Mendeleev organise the elements?
In order of their atomic weights then in a periodic pattern.
Why did scientists believe Mendeleev’s periodic table?
He left space for undiscovered elements and predicted the properties of them. When the elements were discovered his predictions were accurate.
How does the atomic number of an element link to the periodic table?
The atomic number determines its position.
Hoe does the number of electrons in the outer shell link with the periodic table?
The number of electrons determines its chemical properties and its group number.
What two factors connect electronic structure with reactivity going down the groups?
- The distance between the outermost electrons and the nucleus.
- The number of occupied inner shells.
Give one limitation of Mendeleev’s periodic table.
-Not all elements fit the pattern of ordering by atomic mass.
How does reactivity change going down group 1?
Reactivity increases going down.
How does reactivity going down group 7?
Reactivity decreases going down the group.
Why does reactivity change going down group 1?
The outer electron is easier to lose because the outer shell is further away from the positive nucleus making the attraction weaker.
Why does the reactivity change going down group 7?
The electron in the outermost shell is attracted less strongly because it is further away from the nucleus making it harder to attract electrons.
What are Group 1 elements known as?
Alkali metals
