Distinguish between the following:

a) Physical and chemical change

b) Metallic and non-metallic

c) Atom and isotope

d) Electron affinity and electronegativity

e) Heterogeneous and homogeneous

f) Solute and solvent

g) Pure substance and mechanical mixture

h) Ionic and covalent binding

i) Density and mass

j) Law of conservation of mass, law of definite proportions, and law of multiple proportions

Answer:

(a)PHYSICAL CHANGE:

• This change do not changes the chemical composition of the substance and only changes physical state of the substance.
• It is reversible in nature.
• in case of Physical change, no new product is formed.
• There is no change in chemical properties of the substance. Chemical properties of new and older substance remains unchanged.
• For ex- conversion of ice into water.

CHEMICAL CHANGE:

• This change changes the chemical composition of the substance.
• It is irreversible in nature.
• in case of chemical change, new product is formed.
• There is a change in chemical properties of the substance. Chemical properties of new and older substance are different.
• For ex- Respiration, photosynthesis etc.

(b) Metallic minerals contains metals in them while non-metallic minerals do not contains metals in them

Metallic minerals are malleable and ductile in nature while non-metallic are non-malleable and non-ductile.

Metallic are associated with igneous and metamorphic rocks while non metallic are linked with sedimentary rocks.

Metallic- Copper, Iron-Ore, Non-Metallic- Salt, Gypsum etc.

(c) Atom is defined as the smallest indivisible particle of any body which cannot be further broken.

Isotopes are defined as the atoms having same atomic number but different mass number.

(d) Electronegativity is the property or tendency of any metal which enables to attracts electrons from any other atom.

Electron affinity is defined as the amount of heat energy liberated whenever any atoms tends to acquire electron from any other atom.

(e) Heterogenous mixtures are the mixtures having two or more phases but homogenous mixtures are consists of single phase only.

Heterogenous mixtures do not have uniform composition while homogenous mixtures has uniform composition.

heterogenous particles are bigger in size than the homogenous mixture.

Heterogenous mixtures can be separated easily in components while homogenous mixtures are not easy to separate.

(f) Solution is formed by the dissolving of two substances.

The substance which is being dissolved is called solute.

the substance in which solute is dissolved is called solvent.

For ex- if sugar is dissolved in water then sugar is solute while water is solvent.

(g) Pure substance are the substance which has only one atom or molecule present in them and there is no impurity. There composition is fixed in nature. For ex- elements are compounds are pure substances.

Mechanical mixtures are the substance which has more than one atoms or molecules and there is impurity present in them. There composition is not fixed. For ex- water and sugar.

(h) ionic bonds are formed by the transfer of electrons from one atom to the another.

Covalent bonds are formed by the sharing of electrons between two atoms.

ionic bonds are formed by the positive and negative ions and hence are very strong than the covalent bonds.

(i) Mass is defined as the amount of matter present in any substance while density is defined as the mass per unit volume.

Mass is fixed in nature while density is variable and changes with change in volume.

(j) Law of conservation of mass states that mass can neither be created nor be destroyed in any chemical reaction.

Law of definite proportion states that the chemical composition of elements in any compound is always constant

Law of multiple proportions states that if two or more elements combines to form more than two compounds then their ratio in the compounds is always a whole number.