The modern periodic table Flashcards
Why did not all scientists think the periodic table was important?
Because there wasn’t enough evidence to suggests the elements fitted into the gaps.
Once convincing evidence was collected in favour of the periodic table what did scientists use it for?
To predict the properties of elements.
What is the modern periodic table based on?
Electronic structure in order of atomic number.
Using the electron arrangement what can you predict?
The elements chemical properties.
What are electrons in an atom set out in?
Shells which correspond to an energy level.
Apart from transition metals, what do elements in the same group have?
The same number of electrons in their highest occupied energy level (outer shell).
What is the group number equal to?
The number of electrons in the highest occupied energy level, e.g. Group 6 have 6 electrons in the outer shell.
What does the positive charge of the nucleus attract?
Electrons and holds them in place.
What does an electron far from the nucleus mean?
Less of an attraction to the nucleus.
What is shielding?
When there are a lot of inner electrons which ‘get in the way’ of the nuclear charge reducing the attraction.
Why do group 1 elements get more reactive as you go down the group?
Because the combination of increased distance and increased shielding means that an electron in the outer shell is more easily lost. This is because there is less attraction from the nucleus holding it in place.
Why do group 7 elements get less reactive as you go down the group?
Because increased distance and increased shielding means that the outer shell is less likely to gain an electron. This is because there is less attraction from the nucleus pulling electrons into the atom.
