c2. Periodic table Flashcards
How are elements in the periodic table arranged?
In the order of atomic number
Why is the periodic table called this?
Elements with the similar properties occur at regular properties
Why do elements in the same group have similar properties?
They have the same number of electrons in their outermost shell
How were elements arranged in the past?
In order of atomic weight
What were the problems with the early periodic table?
Not all of the elements have been discovered and when elements were placed in order of atomic weight, they ended up in the same group
How did the Mendeleev overcome the problems of the early periodic table?
he left gaps for undiscovered elements and he changed the order of some elements
What type of ions do metals form?
Positive
What type of ions do non-metals form
Negative
Where are metals found in the periodic table?
On the left and towards the bottom
Where are nonmetals found on the periodic table?
On the right towards the top
What are the elements in group 0 known as?
Noble gasses
Why are elements in group 0 unreactive?
The atoms have a stable arrangement of electrons. They have full outermost shells.
Why are elements in group 0 monoatomic?
They have a full shell and do not lose or gain electrons
What happened to the boiling point down group 0?
Boiling point increases
What are elements in group one known as?
Alkali metals
What happens to reactivity down group one?
It increases
Why does reactivity increase in group one?
the group atoms get bigger there is a weaker attraction between the nucleus and so it becomes easier to lose electrons
What happens when a group one element reacts with oxygen?
Alkali metal + oxygen = metal oxide
What happens when a group one element reacts with chlorine?
Alkali metal + chlorine = metal chloride
What happens when a group element reacts with water?
Alkaline metal + water = metal hydroxide + hydrogen
What are the elements in group 7 called?
Halogens
Why does reactivity decrease down group 7?
the group atoms get bigger there is a weaker attraction between a nucleus so if it becomes harder to lose electrons
Why are the halogens in group 7?
They have seven electrons in the outermost shell
What colour vapour does fluorine have?
Yellow
