STUDY QUESTIONS 1. (a) Define matter. Name its three states with one example each. (b) What is matter comprised of ? Explain briefly. 2. (a) Define liquid. (b) Explain why liquids can flow but are not compressible. 3. (a) What is gas? Give two examples. (b) Distinguish between solid, liquid and gas on the basis of free surfaces. 4. Why do gases have no definite shape or volume? 5. Find the odd one out of : Table, vacuum, chalk, chair and stone. 6. Distinguish between the properties of a solid, a liquid and a gas with respect to : (a) intermolecular forces. (b) intermolecular spaces. (c) how to contain them (d) compressibility (e) position of molecules with each other.
Answers
Answer:
1
A
There are three states of matter are:
(i) Solid (ii) Liquid (iii) Gas
1. Solid State: The molecules are very close to each other hence intermolecular spaces are small and intermolecular force is, strong.
Hence solids have a definite volume, rigid, retain definite shape, and are incompressible.
2. Liquids: The molecules are less closely packed have more intermolecular spaces than solid, less strong forces than solids. Hence liquids have a definite volume but no definite shape. They take the shape of the container In which they are put in.
3. Gases: The molecules in the gases are for apart with the weakest force of attraction. Hence, gases have neither a definite volume nor definite shape and compressible.
B
Matter is composed of atoms. Atoms make molecules and compounds, which, in turn, create larger substances. Essentially everything around us is matter since all objects around us are made of atoms. By definition, matter is anything that has mass and takes up space.
2 a
A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Like a gas, a liquid is able to flow and take the shape of a container. Most liquids resist compression, although others can be compressed
b
Because the particles can move, liquids don't have a definite shape, and they can flow. Because the particles are still packed close together, liquids can't easily be compressed and keep the same volume
3a
Gas is a state of matter that has no fixed shape and no fixed volume. Gases have lower density than other states of matter, such as solids and liquids.
Examples of gases are oxygen at room temperature (approximately 20 ºC or 68 ºF), hydrogen at room temperature
b
Solution :
In solids-
Here the molecules are very tightly packed and there is no or very less intermolecular space and there is high intermolecular force of cohesion.
The molecules do not move about their mean position and thus solids have a definite shape and volume
In Liquids-
Here the molecules are less tightly packed as compared to solids and also there is less force of intermolecular attraction. The intermolecular distance is greater than that in the solids. Thus, they don't have a definite shape but acquire the shape of the vessel in which they are contained but have a definite volume at a given temperature.
In gases-
Here the molecules are far apart from each other i.e. have the greatest intermolecular distance which result into the weakest intermolecular forces of attraction. The molecules as are not bound by and strong force move about freely and thus gases do not have a definite shape and also do not have any definite volume.
4
Gases do not have a definite shape or volume because the molecules in gases are very loosely packed, they have large intermolecular spaces and hence they move around. The force of attraction between molecules is also very less, as a result gases acquire any shape or any volume.
5
vacuum
6
Shape
Solid They have a definite shape
Liquid They do not have a definite shape
Gases They do not have a definite shape
2. Volume
Solid They have a definite volume
Liquid They do not have a definite volume
Gases They do not have a definite volume
3. Density
Solid They have high-density
Liquid Liquids have less density than solids Gases
Gases have the least density
4. The kinetic energy of particles
Solid Least
Liquid More than solids
Gases Maximum
5. Compressibility
Solid Negligible
Liquid Low
Gases High
1.a) matter has mass occupies space and can be perceived by our senses.
solid ex:gold piece,liquid ex:milk,gas ex:L.P.G
b) matter is made up of extremely small particles known as atoms.
an atom is the smallest possible unit of matter that exhibits all the properties of that matter. atoms combine to form another minute particle called molecule.