bonding, structure... Flashcards
what 3 ways can atoms chemically bond (join together) in?
ionic bonding, covalent bonding or metallic bonding
what does ionic bonding involve?
an attraction between oppositely charged ions.
where are ionic bonds found?
in compounds made of metals and non-metals.
what does covalent bonding involve?
covalent bonding involves 2 atoms sharing 1 or more pairs of electrons.
where are covalent bonds found?
in most non-metal elements and in compounds of non-metals.
what does metallic bonding involve?
involves an attraction between positively charged ions and negatively charged, delocalised electrons.
where are metallic bonds found?
in metals and alloys (mixtures of metals and other substances).
When atoms form ions what do they try to do?
fill up or empty their outer electron shell
what happens in ionic bonding?
a metal atom transfers electrons to a non-metal atom, allowing both of them (the metal and non-metal) to have a full outer electron shell.
what do group 1 metals always lose to form?
they always lose 1 electron to form positive ions with a charge of +1
give an eg of the electron being lost to form positive ions with a charge of +1
a sodium atom (Na), with the electronic structure (2,8,1), loses its outer electron when forming an ion to make Na+.
what do group 2 metals always lose to form?
Group 2 metals always lose 2 electrons to form doubly positive ions.
give an eg of two electrons being lost to form doubly positive ions.
a magnesium atom (Mg), with the electronic structure (2,8,2), loses both its outer electrons when forming an ion to make Mg2+.
what do non metal atoms (groups 6 n 7) always gain to form?
electrons to form negative ions.
give an eg of electrons being gained to form negative ions
a fluorine atom (F), with the electronic structure (2,7), will gain an electron when forming an ion to make F-.
noble gases (group 0) already have a full?…
outer shell.
what don’t noble gases normally form with other elements?
ionic bonds with other elements.
what wil the GROUP no. in the periodic table tell you about an atoms outer shell?
The group number in the periodic table tells you the number of electrons in an atom’s outer electron shell.
whats are ions?
charged particles
how are ions created?
They are created when an atom or molecule gains or loses electrons.
what does gaining electrons create (in an ion)? what about losing electrons?
Gaining electrons creates a negatively charged ion; losing electrons creates a positively charged ion.
what are positive ions also known as?
cations
what are negative ions also known as?
negative ions
when are positive ions usually created?
when an atom or molecule loses electrons.
what can the metals in group 1 n 2 easily lose and why?
they can easily lose electrons. to become positively charged ions.
how are negative ions usually created?
when an atom or molecule gains electrons
what are the non metals ingroup 7 most likely to gain?
electrons to fill up their electron shell and become negatively charged.
what can ions be:
Single elements (e.g. F-).
A group of elements with an overall charge (e.g. SO42-).
