C2 - The periodic table Flashcards
(22 cards)
How is the periodic table ordered?
By atomic number
How were 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 the periodic table?
To leave room for undiscovered elements
Why do elements in the same groups have similar properties?
They have the same number of electrons in their outer shell
Where are non-metals located?
The right
What name is given to group 1 elements?
Alkali metals
Why are group 1 called the alkali metals?
They react with water to form an alkali and are metals
What is the general equation for group 1 plus oxygen?
Metal + Oxygen —> Metal oxide
What is the general equation for group 1 plus chlorine?
Metal + Chlorine —> Metal chloride
What is the general equation for group 1 plus water?
Metal + water —> Metal hydroxide + Hydrogen
How does the reactivity of group 1 change down the group?
Increasing reactivity downwards
Why does the reactivity increase down group 1?
- Larger atoms
- Weaker electrostatic forces of attraction between outer electrons and nucleus
- Easier to lose electrons and react
What is group 7 called?
Halogens
What are the first 4 halogens?
F2, Cl2, Br2, I2
How do melting points change down group 7?
Increasing melting point downwards
How does the reactivity change down group 7?
Decreasing reactivity downwards
Why does the reactivity decrease down group 7?
- Larger atoms
- Weaker electrostatic forces of attraction
- Harder to gain electrons
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 group 0?
The noble gases
Why are noble gases inert?
They have a full outer shell so don’t react easily
How do the melting points of noble gases change down the group?
Increase melting point downwards
