write in brief...........plz solve now.. all the correct answer will be marked as brainlist
Answers
Answer:
1. mercury and gallium
2. graphite
3. somke in air
4. steel
5. milk
6. a mixture is a material made up of different substances combined physically
7. a. mixtures are not combined chemically
b. mixtures can be separated by simple physical methods
c. the property of the mixture remains same as that of it's constituents
8. exothermic reaction is a reaction in which heat is emitted while as endothermic reaction is a reaction in which heat us absorbed
Answer- The above question is from the chapter 'Is Matter Around Us Pure?'.
1. Two liquid metals are Mercury (Hg) and Gallium (Ga).
2. Graphite is a non-metal which is an excellent conductor of electricity.
3. Nitrogen dioxide (NO₂) is an example of gas in a gas mixture (smoke).
4. Brass is a homogeneous solid-solid mixture (alloy).
5. Milk is a colloidal solution that can be used for drinking.
6. Mixture is a combination of two or more pure substances mixed in a variable ratio.
7. Three characteristics of a mixture are:
i) Components of a mixture are present in variable ratio.
ii) They can be separated by simple physical methods.
iii) Components of a mixture retain their own properties.
8. Exothermic reactions are those reactions in which energy is released while endothermic reactions are those in which energy is absorbed.
9. Water is a compound because:
i) Components of water i.e. hydrogen and oxygen combine in a fixed ratio of 1:8 by mass.
ii) They can be separated only be electrochemical or chemical methods.
iii) Properties of water and properties of its components differ from each other.
10. Metalloids are those substances which show the properties of both metals and non-metals.
Examples: Antimony (Sb) and Geranium (Ge)
11. i) A compound is a pure substance in which elements are combined in a fixed ratio by mass while a mixture is composed of constituents mixed in a variable ratio.
ii) Components of a compound can be separated only be electrochemical or chemical methods while components of a mixture can be separated by simple physical methods.
iii) Properties of a compound are different from its components while properties of a mixture are not different from its components.
12. (The diagram has been attached).
Salt is separated from sea water by the process of evaporation.
Principle- This method is used to separate a non-volatile component or solute (salt) dissolved in a volatile component or solvent (water). Solid component is solute (salt) and is soluble in liquid and we need one component i.e. solute.
At the end, water will evaporate and salt will be left in the watch glass.
(The diagram has been attached.)
