The Periodic Table Flashcards
(26 cards)
How is the modern Periodic Table ordered?
by atomic number
How were the early lists of elements ordered?
by atomic mass
Why did Mendeleev swap the order of some elements?
to group them by their chemical properties
Why did Mendeleev leave gaps in his Periodic Table?
leave room for elements that had not yet been discovered
Why do elements in a group have similar chemical properties?
have the same number of electrons in their outer shell
Where are metals and non-metals located on the Periodic Table?
metals to the left, non-metals to the right
What name is given to the Group 1 elements?
alkali metals
Why are the alkali metals named this?
they are metals that react with water to form an alkali
Give the general equation for the reaction of alkali metals with oxygen.
metal + oxygen → metal oxide
Give the general equation for the reaction of alkali metals with chlorine.
metal + chlorine → metal chloride
Give the general equation for the reaction of alkali metals with water.
metal + water → metal hydroxide + hydrogen
How does the reactivity of the alkali metals change down the group?
increases (more reactive)
Why does the reactivity of the alkali metals increase down the group?
they are larger atoms, so the outermost electron is further from the nucleus
What name is given to the Group 7 elements?
halogens
Give the formulae of the first four halogens.
F, Cl, Br, I
How do the melting points of the halogens change down the group?
increase (higher melting point)
How does the reactivity of the halogens change down the group?
decreases
Why does the reactivity of the halogens decrease down the group?
the outermost shell is further from the nucleus
What is a displacement reaction?
when a more reactive element takes the place of a less reactive one in a compound
What name is given to the Group 0 elements?
noble gases
Why are the noble gases inert?
they have full outer shells so do not need to lose or gain electrons
How do the melting points of the noble gases change down the group?
increase (higher melting point)
How did mendelev group the table?
Chemical properties.
Why is group 8 also called group 0
Is has a full outer shell
