Topic 2 - the periodic table Flashcards
What did Mendeleevs periodic table do?
Left gaps for the unknown elements, which when discovered matched his predictions.
What does the number of electrons in the outermost shell determine?
What group number it will be in
Why are the noble gases in group 0 unreactive?
Because of their very stable electron arrangements
What is group 1 also known as and what do their melting points and boiling points do?
The alkali metals, as you go down the group, the melting and boiling points decrease
What does the reactivity of the alkali metals do as you go down the group?
Increases
What do the halogens form when sharing electrons between other non-metals?
Covalent compounds
What does the reactivity of the halogens do as you go down the group?
Decrease
Three factors that electrostatic attraction depends on?
- distance between outermost electrons and nucleus
- number of occupies inner shells of electrons (provides shielding effect)
- size of positive charge on the nucleus
Transition elements don’t react …… with oxygen or water
Vigorously
What are transition elements like compared to alkali metals?
- higher melting points and densities
- stronger and harder
- much less reactive
Transition elements and compounds are good for?
Important industrial catalysts
