Viraf J. Dalal solutions for New Simplified Middle School Chemistry [English] Class 7 chapter 6 - Metals and Non-metals [Latest edition]

Give the common name and chemical name of an ore of:

(a) zinc (b) aluminium (c) iron.

Distinguish between the physical properties of metals and non-metals with reference to:

(a) lusture (b) malleability (c) ductility (d) tensile strength (e) sonority (f) conduction of heat and electricity (g) melting and boiling point (h) density.

Name the following:
or

With reference to the physical properties of metals and non-metals, state the following exception.

A metal which is liquid at room temperature.

With reference to the physical properties of metals and non-metals, state the following exception.

a non-metal which sublimes and is non-lustrous

With reference to the physical properties of metals and non-metals, state the following exception.

A non-metal which has low tensile strength

With reference to the physical properties of metals and non-metals, state the following exception.

A non-metal which conducts electricity.

With reference to the physical properties of metals and non-metals, state the following exception.

A metal which floats on water.

With reference to the following metals state their use in daily life metal:

copper

With reference to the following metals state their use in daily life metal:

iron

With reference to the following metals state their use in daily life metal:

Aluminium

With reference to the following metals state their use in daily life metal:

Magnesium

With reference to the following metals state their use in daily life metal:

Zinc

With reference to the following metals state their use in daily life metal:

Lead

With reference to the following metals state their use in daily life metal:

Silver

Describe a simple experiment to prove that a copper wire conducts electricity, but a piece of coal does not.

Differentiate between metals and non-metals with reference to –
(a) number of electrons in outer or valence shell
(b) formation of cation and anion
(c) reaction with dilute acids.

Give a reason why – properties of metals are related to their activity or reactivity series of metals. Explain the same with reference to potassium and iron in the series.

Give the basic demarkation of the Modern Periodic Table into metals, metalloids and non-metals with special reference to halogens and noble gases.

Give a reason why the non-metals – halogens and noble gases are placed in separate groups of the periodic table with special reference to their difference in properties.

State what are metalloids.

Name the elements recognised as metalloids.

Compare the properties of metalloids with those of metals.

State the uses of three different metalloids.

Explain the term – rusting and give a word equation for the formation of rust. If polished iron nails are kept in three separate test tubes, state the contents in each test tube required, to prove the conditions for rusting.

State why telegraph poles are painted with aluminium paint.

Give a reason why oiling or greasing is done on the exposed moving iron parts of machinery and not preferred on heavy stationary iron parts.

State why galvanization, tinning and chromeplating are used as three different processes for coating specific articles for prevention of rusting.

Give a reason why rust turns moist red litmus blue.

Give a reason why a green deposit is seen on the surface of an article of copper

Give a reason why iron objects rust easily but the iron pillar at Qutab Minar has not rusted over the years.

State a specific reason for using steel in automobiles.

State a specific reason for using gold in jewellery

State a specific reason for using copper in electrical cables

State a specific reason for using zinc in galvanizing

State a specific reason for using lead in bullets

State a specific reason for using magnesium in fireworks.

Complete the statement given below, by filling in the blank with the correct word:

The ability of a metal to produce a reasonant sound ______.

Complete the statement given below, by filling in the blank with the correct word:

A metal which floats on water _____

Complete the statement given below, by filling in the blank with the correct word:

A non-metal that leaves a mark on paper _______

Complete the statement given below, by filling in the blank with the correct word:

A non-metal which allows an electric current to pass through it ______.

Complete the statement given below, by filling in the blank with the correct word:

A non-metal added to swimming pools to kill germs_____.

Give reason for the following:

Metals form cations while non-metals form anions.

Give reason for the following:

Potassium reacts vigorously with cold water while copper does not react with water or steam.

Give reason for the following:

Rusting reduces the structural strength of iron.

Give reason for the following:

A suspension of rust is basic in nature.

Give reason for the following:

Galvanized steel is not used for articles used for edible applications.

Name the following:

The most reactive halogen.

Name the following:

A metal used in packaging.

Name the following:

The chemical compound responsible for the green deposit on the surface of articles of copper.

Name the following:

A metal used in flexible pipes.

Name the following:

A halogen which is a solid at room temperature.

Select the appropriate option for the following statement:

The element placed in the extreme left of the Modern Periodic Table.

Select the appropriate option for the following statement:

The element which shows properties of both metals and non-metals.

Select the appropriate option for the following statement:

The element from the halogen family which is most abundant

Select the appropriate option for the following statement:

The element which is noble gas and radioactive in nature.

Select the appropriate option for the following statement:

The element which is a noble metal.

State whether the statement given below is true or false. If false write the correct statement.

Lead pencils contain lead.

State whether the statement given below is true or false. If false write the correct statement.

The chemical name of rust is iron [III] oxide.

State whether the statement given below is true or false. If false write the correct statement.

Silicon is an example of a metalloid.

State whether the statement given below is true or false. If false write the correct statement.

Either oxygen or moisture is essential for rusting.

State whether the statement given below is true or false. If false write the correct statement.

Graphite is a lustrous non-metal which conducts electricity.