to divide
non-metal ,
e.g. All the elements in the Mendeleyev's Periodic System are divided into metals and non-metals.
The elements are divided into metals and non-metals according to their physical and chemical properties.
Chemical properties are much more important than physical properties for deciding whether (if) this or that element is a metal or a non-metal.
solid ;
liquid ;
gas
e.g. Metals and non-metals may be solid and liquid.
All metals are solid except ( ) mercury which is liquid.
density ,
potassium
sodium
e.g. Metals have a high density (except potassium and sodium), while non-metals usually have a low density.
malleable (= ductile)
e.g. Metals are malleable while solid non-metals are brittle.
temperature
point
melting point (= melting temperature) ()
boiling point
to melt
melting
to boil
boiling
e.g. Metals have high melting and boiling points while non-metals have low melting and boiling points.
conductor ( ..)
poor onductor
to heat
heat ,
e.g. Metals are good conductors of heat and electricity while non-metals are poor conductors of heat and electricity (except graphite () which is a good conductor of electricity).
to draw (drew, drawn) ,
to draw into wire
e.g. Metals are ductile, that is (-) they can be drawn into wire while non-metals cannot be drawn into wire.
salt
oxide
basic xide
metallic xide
acid
acidic xide ( )
to react with
to form ,
form
to form salts (oxides etc.) ( ..)
soluble
dilute ,
e.g. Diluteacids reacting with metals form different salts.
ion
positive (negative) ion ()
to liberate () ( . )
anode ( )
cathode ( +)
electrolyses
hydrogen
to mould
to press
pressure
Match the word or word phrase (left column) and its translation (right column). Write them down in your notebooks.
) :
| 1) non-metal 2) solid 3) liquid 4) gas 5) density 6) temperature 7) boiling 8) melting 9) conductor 10) heat (heating) 11) electricity 12) salt 13) oxide 14) acid 15) ion 16) anode 17) cathode 18) electrolysis 19) hydrogen 20) form 21) pressure | a) b) c) d) e) , f) g) h) i) j) k) () l) m) n) , o) p) q) r) s) t) u) |
b) :
|
|
|
| 1) solid 2) liquid 3) malleable (= ductile) 4) poor conductor 5) basic oxide 6) metallic oxide 7) acidic oxide 8) negative 9) low 10) soluble 11) dilute 12) positive 13) high | a) b) c) d) e) f) g) h) i) j) k) l) m) |
c) :
| 1) to divide into 2) to form salts 3) to react with 4) to draw into wire 5) to liberate 6) to melt 7) to heat 8) to press 9) to mould | a) b) c) () d) e) f) () g) h) i) |
Read Text
Text
METALS AND NON-METALS
There are 105 elements in the Mendeleyev's Periodic System. These elements are divided into two groups: the metals and the non-metals. Here is a table showing the difference (, ) between metals and non-metals.
Physical properties of metals:
1. Solid at room temperature (mercury is the only liquid metal).
2. Have a high density (except potassium and sodium).
3. Can be moulded by pressure, that is they are malleable.
4. Have high melting and boiling points.
5. Can be drawn into wire, i.e. (that is) they are ductile.
Physical properties of non-metals:
1. Many are liquids and gases at room temperature.
2. Density is usually low.
3. Solid non-metals are brittle.
4. Have low melting and boiling points.
5. Cannot be drawn into wire.
Chemical properties of metals:
1. Have basic oxides.
2. React with dilute acids forming salts.
3. Form positive ions.
4. Are liberated at the cathode during electrolysis.
Chemical properties of non- metals:
1. Have acidic oxides.
2. Salts of non-metals do not exist.
3. Form negative ions.
4. Are liberated at the anode during electrolysis.
