Chapter 2 - Chemistry Flashcards
What are group 1 elements called?
Alkali metals
What are group 7 elements called?
The halogens
What do alkali metals react with?
Water and oxygen
In group 1, how do the elements change (in terms of their reactivity)
They get more reactive as you go down the group
In group 7, how do the elements change (in terms of their reactivity)
They get more unreactive the further you go down the group
Why does reactivity increase in group 1?
The atoms get larger so the single electron in the outermost shell is attracted less strongly to the nucleus.
Why does reactivity decrease in group 7?
Because their atoms gain an electron in their outermost shell
What two changes did Mendeleev make to the periodic table?
He left gaps.
He switched the order of some elements.
How are chemical elements ordered?
They are placed in order of their atomic (proton) number in the periodic table.
What does the group number in the periodic table tell you?
The number of electrons in the outermost shell.
What is the main difference between metals and non-metals?
Metals conduct electricity and non-metals generally are electrical insulators.
What are group 7 elements called?
The halogens
What are the properties of halogens?
They have low melting and boiling points, their melting and boiling points increase going down the group.
They are poor conductors of heat and energy.
What does the electronic structure of the halogens determine?
The way they react with other elements.
Why does the reactivity increase going down the group in group 1?
The atoms get larger so the single electron in the outermost shell (highest energy level) is attracted less strongly to the positive nucleus.
