Viraf J. Dalal solutions for New Simplified Middle School Chemistry [English] Class 7 chapter 1 - Matter and Its Composition [Latest edition]

Explain the meaning of the term matter with special reference to the term ‘substance’.

Name the three states of matter.

On what basis are the three states classified of matter.

Each of the three states of matter has mass. Explain with the help simple experiments – that each state of matter has mass.

A measuring cylinder is filled with water to a particular mark. A piece of solid is immersed inside the measuring cylinder. State why the level of water in the measuring cylinder will rise up. If the solid is removed, what will be the new level of the water in the measuring cylinder? Give a reason for your answer.

A glass beaker is half-filled with water and an empty glass tumbler is inverted & lowered inside the glass beaker. State your observations on tilting the tumbler below the level of the water in the glass beaker. Give a reason for your answer.

Differentiate the general properties of solids, liquids and gases in the form of a table — with reference to mass

Differentiate the general properties of solids, liquids and gases in the form of a table — with reference to space.

Differentiate the general properties of solids, liquids and gases in the form of a table — with reference to volume.

Differentiate the general properties of solids, liquids and gases in the form of a table — with reference to shape.

Differentiate the general properties of solids, liquids and gases in the form of a table — with reference to compressibility.

Differentiate the general properties of solids, liquids and gases in the form of a table — with reference to density.

Differentiate the general properties of solids, liquids and gases in the form of a table — with reference to free surfaces.

Differentiate the general properties of solids, liquids and gases in the form of a table — with reference to free diffusion.

State in which of the three states of matter:

Are the atoms or particles far apart

State in which of the three states of matter:

The space between the particles is minimum.

State in which of the three states of matter:

The force of attraction between the particles is very weak.

State in which of the three states of matter:

The movement of the particles is neither about their own positions nor in any random direction.

Give a reason why –

Solids have a definite volume & a definite shape.

Give a reason why –

Liquids have a definite volume but no definite shape.

Give a reason why:

Gases have no definite volume and no definite shape.

Particles of matter possess energy due to their random motion. Compare the particles in a solid, liquid and in gas with reference to the amount of kinetic energy possessed by each.

Describe simple experiment to show that particles of matter have the intermolecular attraction

Describe simple experiment to show that particles of matter are closely packed in solids and less in liquids.

A crystal of iodine is placed in a closed flat bottom flask and heated. State how you would conclude from the observations seen, that interparticle space is minimum in solids and maximum in gases.

Explain the term ‘interconversion of matter’ with ice as a starting material.

State the term which refers to the conversion of a substance on heating from.

1. solid-state to liquid state
2. liquid state to vapour state
3. vapour state to liquid state
4. liquid state to solid-state.

Give a reason why solids and liquids co-exist at their melting points.

Match the characteristics of the three states of matter in List I with their correct answer from List II.

Fill in the blanks:

Matter is defined as anything that occupies _______ and has _______

Fill in the blank:

The three states of matter are classified on the basis of differences of certain _________.

Fill in the blank:

Matter made up of one kind of particle is said to be _________.

Fill in the blank:

Particles in a gas possess ___________ kinetic energy.

Fill in the blank:

The intermolecular force of attraction is ___________ in solids.

Give a reason why:

Gases have no definite volume and no definite shape.

Give a reason for the following:

Liquids have one free upper surface only.

Give a reason for the following:

Globules of mercury kept in a petri dish, which is shaken slowly, come together forming a big globule.

Give a reason for the following:

A crystal of iodine on slow heating in a closed flask turns into vapours and fills the complete flask.

Give a reason for the following:

An empty tumbler lowered into a glass beaker containing water, on tilting shows bubbles of air coming out, but when not tilted, no bubbles are seen.

State the correct term from A, B, C, D, E or F in List II which represents the – change of state of matter or its relevant property from List I

Match the arrangement of atoms in the three states of matter in List I with the correct state in List II.