Download App

Is Matter Around Us Pure? — Science STD 9 — Question

CBSE BoardEnglish MediumSTD 9ScienceIs Matter Around Us Pure?5 Marks
Question
Give the main differences between physical changes and chemical changes.
✓

Answer

PHYSICAL CHANGE CHEMICAL CHANGE
iNo, new substance is formed in a physical change. iNew substance is formed in a chemical change.
iiIt is a temporart change.iiA chemical change is a permanent change.
iiiIt is easily reversible.iiiThis process is usually irreversible.
ivVery little heat or light energy is usually absorbed or given out in this process.ivA lot of heat or light energy is absorbed or given out in this process.
vMass of substance does not alter.vMass of substance does alter in this process.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Answer the questions.[Che-5M]" from Is Matter Around Us Pure?→Is Matter Around Us Pure? — all question types→Science STD 9 question papers→CBSE Board STD 9 question papers→CBSE Board question paper generator→

Similar questions

If the back of your hand is moistened with alcohol, you will find that it rapidly becomes dry. Why is it that while it is drying, your hand feels cool?
→
There are three substances X, Y and Z. The substance X does not have a fixed melting point or boiling point and it still shows the individual properties of its constituents. The substance Y is a pure substance which occurs in nature as such. The substance Y has a fixed melting point and boiling point but it cannot be broken down into simpler substances by any chemical means. The substance Z is also a pure substance whose properties are entirely different from those of its constituents. The substance Z can, however, be divided by electrolysis into two substances which belong to the same class of substances as Y.
  1. What type of substance could X be? Name one substance like X.
  2. What type of substance could Y be? Name one substance like Y.
  3. What type of substance could Z be? Name one substance like Z.
  4. Whish process involves absorption or release of an appreciable amount of energy: formation of substance X or formation of substance Z?
  5. Name the three groups into which all the substances like Y are divided on the basis of their properties.
→
An element X forms the following compounds with hydrogen, carbon and oxygen:
H2X, CX2, XO2, XO3
→
Give the chemical formulae for the following compounds and compute the ratio by mass of the combining elements in each one of them.
  1. Ammonia
  2. Carbon monoxide
  3. Hydrogen chloride
  4. Aluminium fluoride
  5. Magnesium sulphide
→
How can you obtain pure water from a salt-water mixture (or salt-solution)? Draw a meat and labelled diagram of the apparatus you would use to obtain pure water from a salt-water mixture (or salt-solution).
→
How will you separate a mixture of mercury, oil and water?
→
By which physical process the fragrance of burning an incense stick spreads all around?
→
Which contains more molecules, 10g of sulphur dioxide (SO2) or 10g of oxygen (O2)?
(Atomic masses: S = 32u; O = 16u)
→
Which has more number of atoms, 100grams of sodium or 100grams of iron (given, atomic mass of Na = 23u, Fe = 56u)?
→
List five characteristics by which compounds can be distinguished from mixtures.
→