Matter Around Us Flashcards
Not all things that we see or feel are matter. __________ They are not matter.
For example, sunlight, sound, force and energy neither occupy space nor have any mass.
In the modern periodic table there are _____ elements known to us, ____ of which are naturally occurring while the remaining ______ have been artificially created. But from these 118 elements, billions of compounds are formed- some naturally occurring and some artificial. Isn’t that amazing?
118
92
26
Who used the name element for any substance that cannot be broken down further, into a simpler substance. This definition can be extended to include the fact that each element is made up of only one kind of atom
Robert boyle
Atom:
The smallest unit of an element which may or may not have an independent existence but always takes part in a chemical reaction is called atom.
Molecules:
The smallest unit of a pure substance, which always exists independently and can retain physical and chemical properties of that substance is called a molecule.
When two or more elements combine chemically to form a new substance, the new substance is called a ________. For example, cane sugar is made up of three elements carbon, hydrogen and oxygen. The chemical forumula of cane sugar is C₁₂H22 O11
compound
A compound has properties that are different from those of the elements from which it is made
Common salt, also known as sodium chloride, is a compound. It is added to give taste to our food. It is a compound made up of a metal, sodium, that reacts violently with water and a poisonous non-metal, chlorine.
Compounds of _________ are used in fertilizers,
______ compounds are of immense importance in the computer industry.
Compounds of _______ are used in our toothpastes as they strengthen our teeth.
1 phosphorous, nitrogen and potassium
2 Silicon
3 fluorine
A _________ is an impure substance. It contains two or more kinds of elements or compounds or both physically mixed together in any ratio
mixture
Element
Made up of only one kind of atom.
The smallest particle that retains all its properties is the atom,
Cannot be broken down into simpler substances
Compound
Made up of more than one kind of atom.
The smallest particle that retains all its properties is the molecule.
Can be broken down into elements by chemical methods.
Blood is not a pure substance… It is a mixture of various components such as
platelets, red and white blood corpuscles and plasma.
Mixture
It contains two or more substances
The constituent may be present in any proportion.
They show the properties of their constituents.
The components may be separated easily by physical methods.
Compound
It is a single substance
Theconstituents are present in definite proportions.
They do not show the properties of the constituent elements.
The constituents can only be separated by one or more chemical reactions.
A mixture in which the components cannot be seen separately is called a
homogeneous mixture
every part of the mixture has the same properties
homogeneous mixtures.
Tap water, milk, air, ice cream, sugar syrup, ink, steel, bronze and salt solution
A mixture in which the components can be seen separately is called a
heterogeneous mixture..
It does not have a uniform composition and properties
heterogeneous mixture.
Soil, a mixture of iodine and common salt, a mixture of sugar and sand, a mixture of oil and water, a mixture of sulphur and iron filings and a mixture of milk and cereals
Certain solid substances when heated
when cooled give b
process is known
Iodine, camphor, a
EX Hong
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Camphor, is a
change directly from solid to gaseous state household. It without attaining liquid state. The vapours when cooled give back the solid substance. This process is known as
sublimation
Sublimation
Air freshener
Moth ball
Camphor
Solid and solid
Heterogeneous mixture
Method of separation
Handpicking, sieving, winnowing, magnetic separation, sublimation.
Heterogeneous mixture
Insoluble Solid and liquid
Method of separation
Sedimentation and decantation, loading, filtration, centrifugation
Heterogeneous mixture
Two immiscible liquid
Decantation, separating funnel
Homogeneous mixture
Soluble Solid and liquid
Method of separation
Evaporation, distillation, crystallisation
Homogeneous mixture
Two miscible liquid
Fractional distillation
Homogeneous mixture
Solution of two or more solids in a liquid
Method of separation
Chromatography
_______ is the process by which fine insoluble solids from a solid- liquid mixture can be separated in a machine called a centrifuge
Centrifugation
Centrifugation used in
to separate cream from milk.
In washing, machines, this principle is used to squeeze out water from wet clothes.
Centrifugation is also used in pathological laboratories to separate blood cells from a blood sample.
________ method works on the principle of difference in solubility of two immiscible liquids in a suitable solvent..
Solvent extraction
mixture of water and oil can be separated using a
separating funnel
Solvent extraction method
________ method is used in pharmaceutical and petroleum industries
Solvent extraction
______ is an old practice done for years. It is the main process in perfume development and it is also used to obtain dyes from various sources.
Solvent extraction