5.1.2 Periodic Table Flashcards
Elements in the periodic table are arranged by what?
Atomic number
What can be said about elements in the same group (column)?
They have the same number of electrons in their outer shell.
This means they have similar chemical properties.
The early periodic tables arranged element by atomic weight. What problems were there?
They were incomplete and some elements appeared in strange groups if the order of weights was followed strictly.
What did Mendeleev do to solve some issues with early periodic tables?
He left gaps for elements he thought might not have been discovered yet.
Most elements are metals, true or false?
True
When an atom gains or loses electrons, it becomes charged and is known as an….
ion
Metals form positive or negative ions?
Positive
Do metal atoms gain or lose electrons to become positive ions?
Metal atoms lose electrons
Non-metal atoms form positive or negative electrons?
Negative
Do non-metal atoms gain or lose electrons to become negatively charged?
They gain electrons
They get extra electrons
What is the other name for group 0 of the periodic table?
The noble gases
What is special about the noble gases
They have full outer electron shells and so they are unreactive
How many electrons are there in the outer shell of the noble gases?
8 except for helium, which has only one electron shell so it only has 2.
What happens to boiling point as you go down the noble gas group?
Boiling point increases
Why does boiling point increase as you go down the noble gas group?
Because atomic mass increases - this increases forces of attraction that need to be broken by heat energy before the element boils.
