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it matters around us pure notes class 9, is matters around us pure hand written notes
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9 Class Science Chapter 2 Is Matter Around Us Pure ? Notes.
Is matter around us pure notes, class 9 science chapter 2 notes. here we will be learn about MATTERS , Mixture , Solution , Concentration , Suspension , Colloidal solutions , Physical Properties , Physical Change , Chemical Change , Elements , Compounds etc..
Class 9 Science Chapter 2 Is Matter Around Us Pure ? Notes
📚 Chapter = 2 📚
Is Matter Around Us Pure ?
MATTERS :-.
🔹Anything which occupies space and has mass is called matter..
🔹 Matter can be divided in two categories..
( I ) Pure Substance.
( II ) Impure Substances (Mixtures).
( I ) Pure Substance :-.
🔹 Pure substances means that all elements have same chemical properties. A pure substance is made up of same kind of elements..
Pure :- ‘Pure’ word means that there is no mixing in a substance. But according to scientific language all things are mixture of so many substances, not of single one. That’s why they are not pure. E.g. Milk, water, fat, etc..
Substance :- A substance is a kind of matter that cannot be separated into other kind of matter by any physical process. Apure substance is made up of same kind of elements..
What is a Mixture?.
🔹 It is a substance in which two or more substances (element or compound) are simply mixed together in any proportion. .
🔹 Examples :- The air is a mixture of oxygen, nitrogen, carbon dioxide and water vapour..
Types of Mixture :-.
🔹 Mixture is of two types : .
Homogenous mixture .
Heterogenous mixture.
🔶 Homogenous Mixture :- .
🔹 These types of mixtures have no visible boundaries of separation between the various constituents. .
🔹 Example :- Sugar in water. It has a uniform composition throughout its mass. .
🔶 Heterogenous Mixture :- .
🔹 These types of mixtures have visible boundaries of separation between the various constituents..
🔹 Example :- Mixture of sugar and sand. It does not have a uniform composition throughout its mass..
Physical Properties. .
❇️ Physical Change :-.
🔹 When physical properties of a substance change it is known Physical Change. When we convert a substance from one state to another, such as a solid into a liquid or vice-versa, it is also a physical change as only the physical nature of the substance changes without affecting its chemical nature..
🔹 For Example :- Change of ice into water. The chemical properties of water remain the same..
❇️ Chemical Change :-.
🔹 When the chemical properties or chemical composition of a substance gets altered it is called a chemical change. It is also called as a Chemical Reaction. .
🔹 For Example :- Burning of paper.
❇️ Elements :-.
🔹 An element is the simplest form of matter. Elements cannot be broken down into further elements by chemical reactions. .
🔹 Elements are further characterized as Metals, Non-Metals and Metalloids.
🔶 Metals :- Silver, Mercury, Copper, Gold .
Metals are lustrous (shiny) .
Metals conduct heat and electricity .
Metals have a silver-grey or gold-yellow colour .
We can hammer metals and form thin sheets (Malleability) .
We can convert metals into wires (Ductility).
Metals always produce a ringing sound if they are hit (Sonorous).
🔶 Non-Metals :- Carbon, lodine, Chlorine, Oxygen, Hydrogen .
Non-Metals do not conduct heat and electricity .
Non-Metals are not sonorous, lustrous or ductile .
Non-Metals have varied colours .
🔶 Metalloids :- Silicon, Germanium .
They show some properties of metals and some of the non-metals..
❇️ Compounds :-.
🔹 It is a substance that consists of two or more substances. These substances are combined chemically with each other in fixed proportions. The properties of a compound are different than that of its constituents. .