Chem 4: The Periodic Table Flashcards
(18 cards)
How is the modern period 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 properties
Why did Mendeleev leave gaps in his periodic table?
Leave room for elements that he had not discovered yet
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 equations for the reactions of alkali metals with oxygen, chlorine and water
Metal+oxygen —-> metal oxide
Metal+chlorine —-> metal chloride
Metal+water —> metal hydroxide+hydrogen
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, meaning there are weaker electrostatic forces of attraction and more shielding between the nucleus and outer electron, and it is easier to lose the electron
What name is given to group 7 elements?
Halogens
Give the formulae of the first four halogens
F2, CL2, Br2, I2
How do the melting points of the halogens change down the group
Increase (higher melting point)
Why does the reactivity of the halogens decrease down the group?
They are larger atoms, so the outermost shell is further from the nucleus, meaning there are weaker electrostatic forces of attraction and more shielding between the nucleus and outer shell, and it is harder to gain an electron
What is a displacement reaction?
When a more reactive element takes the place of a less reactive one in a compound
Why are Nobel gages inert?
They have full outer shells so do not need to lose or gain electrons
Why are Nobel gages inert?
They have full outer shells so do not need to lose or gain electrons
How do the melting points of the Nobel gases change down the group?
Increase (higher melting point)
