c2.2 try 2 Flashcards
metals:
- appearance
- melting point + boiling point
- state at room temp
- malleable or brittle
- ductile or non ductile
- electrical + thermal conductivity
-shiny
- usually high
- solid
- malleable
- ductile
- good conductors of both
non- metals:
- appearance
- melting point + boiling point
- state at room temp
- malleable or brittle
- ductile or non ductile
- electrical + thermal conductivity
- dull
- usually low
- half solid, half gas
- brittle
- non-ductile
- poor conductivity (insulators)
where are metals and non-metals positioned on the periodic table?
non metals = right
metals = left
how do metals and non-metals differ in terms of how they form ions?
- metals lose electrons when forming ions (positive ions)
- non-metals gain electrons when forming ions (negative ions)
what kind of solution is produced when a metal oxide dissolves in water? (acidic or alkaline)
alkaline solution
what kind of solution is produced when a non-metal oxide dissolves in water? (acidic or alkaline)
acidic solution
what is special about the elements on the boundary of non metals and metals on the periodic table?
some elements have properties of both metals and non-metals
how is an ion formed?
when an atom or group of atoms loses or gains electrons
draw a dot and cross diagram of a chloride ion (atomic number of 17)
2 in first shell, 8 in second shell, 8 in third shell (8th electron must be different to other electrons), as it gains one electron
what kind of bond is formed when sodium and chlorine react?
an ionic compound (as they are a metal and non-metal respectively)
what happens when a metal and non-metal reacts (in terms of electrons), and why does that happen? (2)
an electron/electrons are transferred from the metal to the non-metal (1) so that they both have stable electronic structures (1)
what is the structure of an ionic compound? (in solid state) (2)
- they are regularly (1) arranged with opposite charged ions alternating (1)
ie. + - + - + - + - +
what is the name of the arrangement of an ionic compound?
giant ionic lattice
explain how strong ionic bonds are. (3)
VERY STRONG (1)
- forces of electrostatic attraction between oppositely charged ions (1) caused by transfer of electrons (from metal to non-metal) (1)
what is a covalent bond (in terms of electrons)? (1)
a shared pair of electrons
why do covalent bonds form?
so that both the non-metal atoms can complete their outer shells
how is a covalent bond shown on a dot and cross diagram?
like a venn diagram, with however many shared electrons in the overlapping section (o x) is one pair of shared electrons
give 4 examples of simple molecules?
hydrogen, oxygen, water, carbon dioxide
where is the force of attraction in simple molecules, and what kind of bonds are they?
AND RELATIVE STRENGTH
- force of attraction between nucleus of bonded atom + shared electron -> COVALENT bond - strong
- forces between molecules -> INTERMOLECULAR - weak
limitations of ball-and-stick models? (3)
- size of atom is exaggerated
- length of bond is exaggerated
- suggests that electrons (that make up bonds) do not move
main limitation of a displayed formula model? (1)
- does not show 3D shape of the molecule
(looks like this)
O
/ \
H H
how are the reactions of elements related to the arrangement of electrons in their atoms?
they react in a way to have the most stable arrangement (ie. a full outer shell)
state 3 properties of Mendeleev’s periodic table
- mainly ordered his table in order of increasing atomic mass (some places he changed order based on properties)
- rows and columns for chemical properties
- left gaps for elements he thought had not been discovered yet
