F4 C4 CHEM (GROUP 18 4.3) Flashcards
group 18 known as?
noble gases / inert gases
list first 3 elements in group 18
helium (He)
argon (Ar)
neon (Ne)
other than monoatomic gases, they are also ____ gases ?
colourless
why are noble gases known as monoatomic gases?
this is because noble gases have achieve duplet and octet electron arrangement. they will not share, donate and receive eletrons from any other elements.
list all 4 physical properties of noble gases
low density
insoluble in water
low m.p. and b.p.
doesn’t conduct electricity and heat
how’d you explain forces of attraction?
name and strength of the f.o.a
how much heat is needed to overcome the f.o.a ?
why noble gases have a low melting and boiling point?
nobles gases have a low melting and boiling point because they are attracted by weak Van der Waals force. Little heat is needed to overcome the forces of attraction
what are physical properties?
observable properties
what are chemical properties?
what reaction can it undergo
what does grp 18 elements react with?
noble gases react with water and burn with oxygen
what changes moving down the group?
phy or chem ?
physical properties
what are those physical properties that changes going down the group?
melting and boiling point, atomic size, density
explain the atomic size going down the group
going down group 18, the atomic size increases. This is because the number of shells filled with electrons increases
explain the density going down the group
going down group 18, mass increases faster than volume
explain the melting and boiling point going down the group
going down the group 18, the atomic size of the elements increases. shells filled with electron are attracted by strong Van der Waals force. more heat is needed to overcome forces of attraction.
