chapter 14: the periodic table Flashcards
how are the elements of the periodic table arranged
in increasing proton number
What are horizontal rows of elements in the periodic table called?
periods
what are vertical columns of elements in the periodic table called?
groups
What are elements close to the ‘zig-zag’ line called?
metalloids
name the metalloids
(7 of them)
boron
silicon
germanium
arsenic
antimony
tellurium
polonium
what are the properties of metals
- high melting and boiling points
- shiny
- ductile, malleable
- sonorous
- good conductors of heat and electricity
what are the properties of metalloids
it has properties of metals and non-metals
what are the properties of non-metals
- gaseous or volatile
liquid or dull, brittle solids - low melting points
- poor conductors of heat and electricity
why is there an increase in metallic character with increasing atomic size?
as the valence electrons are further away from the nucleus, the elements have a greater tendency to lose the valence electron to form positive ions
period number = number of _______ _______
electron shells
group number = number of ________ _________
valence electrons
elements on the same group have similar ______________
chemical properties
physical properties of group 1 metals
(alkali metals)
I
- shiny and soft
- very good conductor of heat and electricity
- low melting and boiling points (decreases down the group)
- low density (decreases down the group)
chemical properties of group 1 metals
- alkali metals are highly reactive. to prevent them from reacting with air or water, they are stored under oil.
why are group 1 metals very chemically reactive?
they are all very chemically reactive as they all just have one electron in their outermost shell and therefore form M+ ions (Li+, Na+, K+). As we go down group 1, the reactivity of the alkali metals increases as it becomes easier to lose their outermost electron.
