Learn why electron shells are responsible for the properties of elements, and whether they are stable or have violent reactions.
- An element's reactivity is determined by the number of electrons in the outer shell of its atom.
- To be perfectly stable, an atom requires a full outer shell of electrons.
- The inner shell of every atom can hold only two electrons - as the shells move further away from the nucleus, they can accommodate more electrons.
- Potassium, with a single outer-shell electron, will react with other elements to leave it with a full outer shell.
What makes the element potassium violently reactive?
While the element gold can remain unchanged for thousands of years.
The key to an element's reactivity lies with the number and arrangement of its electrons.
In all atoms, negative electrons move in a relatively huge space around the positive nucleus.
But, crucially, the electrons organize ...
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