Metal and Non - metals - Intro, overview/meaning Flashcards
Total known elements?
115
Elements are divided into? on the basis of?
Metals and Non - metals on the basis on their properties
define malleable
can be beaten with a hammer to form thin sheets w/o breaking
define ductile
can be stretched/drawn to form thin wires
define brittle
breaks on hammering/stretching
chemical Properties of metals -
elements that conduct heat and electricity
metals are ->
malleable and ductile
physical properties
lustrous, hard, strong, heavy, sonorous
example of metals
iron, au, ag, cu, na, k, ca, mg
exception of state
all are solid except mercury -> liquid
during rxn metals form? by?
+ve ions, losing electrons
metals definition chemically
elements (except hydrogen) which form +ve ions by losing/donating electrons ex - AL3+
Metals are called ———– elements
electropositive elements
most abundant metal in earths crust?
al (7%), iron (4%), ca, na, k, mg
properties of non metals ->
x conduct heat/electricity, x malleable/ductile -> brittle, x lustrous -> dull appearance, x sonorous, x strong -> soft
ex of non metals
carbon, sulphur, phosphorus, silicon, H, O2, N, Cl, Br, Iodine, He, Neon, Argon
carbon impt ex -
2 allotropic forms of carbon -> diamond, graphite
total non metals and their divisions -
22, solids -> 10, liquid -> 1 - bromine, gases -> 11
During rxn non metals form? by?
-ve ions by gaining electrons
exception of electrons in non metals?
hydrogen -> losses electrons to form +ve ions
How cn u say non metals are impt?
for lyphie -> carbon compounds form life
how is o2 impt?
saasein + combustion
nitrogen is —— gas? impt?
inert gas, reduces rate of combustion making life safer
how is Sulphur impt?
hair, onion, garlic
most abundant non metal ->?
OXYGEN 50% of our crust, silicon - 26%, phosphorus, Sulphur
best malleable metal
gold and silver
thin sheets are called?
foils
silver foil is used in?
sweets
al foil is used in?
packaging food items, milk bottle caps
iron sheet is used in?
boxes, buckets, drums, water tanks
most ductile metal
gold, 1g of gold = 2 kms
cu - wires, al - wires are used in?
electrical wires
fe wires?
wire gauzes
mg wires?
sci experiemnts in lab
tungsten wires?
filaments of bulbs
explain how metals are good conduction of heat
they allow heat to pass thru em easily
nail demonstration for conduction of heat -
when an al rod is attachd to one end on a stand and other is put near a flame the iron nails stuck to the rod with wax will start dropping down one by one as heat travels from hotter -> colder end nd wax is melted.
conduction of heat in metals is also known as?
thermal conductivity
best conductor of heat?
silver
y are cooking utensils made up of cu, al?
bcs they are gud conductors of heat
poorest conductor of heat?
lead, mercury too
How is heat conducted thru metals?
when heated, atoms gain energy -> vibrate vigorsly the energy is transfrrd to electrons nd the electrons move nd transfer energy to other electrons nd atoms
How are metals good conductors of electricity?
they allow electricity/electric current to pass thru them
electric conduction demonstration
take a bulb a battery nd 2 wires with crocodile clips at the end put an al foil completing the circuit nd the bulb will glow -> yes conduction happens
How are they gud conductos
they have low resistance, meaning high conductivity,
best conductor of electricity
silver
electric wires are of cu and al y?
bcs they r ud conductors of e
bad conductors of elec?
fe and mercury bcs they have high resistance
How rlly does conduction of elec take place?
bcs they contain free e-s and they can move easily thru conducting elec
what is PVC?
poly vinyl chloride which is an insulator and the covering of wires have this plastics covering on it so if we touch we dont hv current die us.
explain lustre in metals
metallic lustre -> jwellery/decor, they are shiny and hence are good reflectors ex - silver in mirrors, after exposure of air they become dull due to the formation of the thin layer of oxide, carbonate, sulphate making the surface corroded, rubbing sandpaper -> removes layer -> shiny again
which metals arent hard?
sodium potassium
which metals arent strong?
sodium potassium
metals usually have high melting and boiling points
fe - 1535c, cu - 1083, sodium - 98, potassium - 64c, GALLIUM - 30, CESIUM - 28 -> MELT IN HAND
High densities of metals mean? exception?
they are heavy substances, sodium potassium
usual color of metals? exceptions?
silver/grey -> cu (reddish brown), au -> yellow
Non metals physical prps?
x malleable, x ductile -> yep brittle, break into pieces when hammered, applicable only to solids
y do non metals not conduct heat/electricity, exception?
no free electrons, carbon (in the form of graphite is a gud conductor) used in electrodes
non metals are not lustrous exception?
iodine
non metals are soft exception?
diamond (v hard) (carbon)
non metals have low melting nd boiling points exception nd details?
diamond, sulphurs m.p - 115, diamonds m.p - 3500
explain the diffrnt colors of non metals
sulphur - yellow, phosprs - white, graphite - black, chlorine - yellowish - green, h and o2 - colorless
metals like lithium, sodium, potassium are clld?
alkali metals they are soft nd hv low densities
