Tag: physical properties of metals and non-metals

Questions Related to physical properties of metals and non-metals

Formula of density is:

  1. $\dfrac{mass}{volume}$

  2. $\dfrac{volume}{mass}$

  3. $\dfrac{mass}{area}$

  4. $\dfrac{area}{mass}$


Correct Option: A
Explanation:

Density, of a substance is define as mass per unit volume. Density $(\delta)$ is equal to mass $(m)$ divided by volume $(V)$. 

$Density = \dfrac{mass}{volume}$

Which of the following is used to galvanize metals, making them resistant to oxidation (rusting)?

  1. Zinc

  2. Iron

  3. Tin

  4. Aluminium

  5. Hydrogen


Correct Option: A
Explanation:

Zinc is used to galvanize metals, making them resistant to oxidation (rusting). Zinc is stronger reducing agent than the metal to be galvanized (such as iron) and hence, zinc can be more easily oxidised. Thus, during corrosion, zinc is oxidised. This prevents corrosion (rusting) of other metal.

Beryllium, when combined with trace of chromium forms a gemstone called___________.

  1. Ruby

  2. Sapphire

  3. Emerald

  4. None of the above


Correct Option: C
Explanation:

When combined with trace amounts of chromium, beryllium takes on a beautiful green hue as the gemstone commonly known as the emerald.

Aluminium foils are used for:

  1. wrapping chocolates and food stuff

  2. to prepare hydrogen

  3. both $A$ and $B$

  4. none of these


Correct Option: C
Explanation:

Aluminium foils are impermeable to oxygen and water; thus are used for wrapping chocolates and foodstuff. 


It can be used for the preparation of hydrogen using the reaction of aluminium foil with a sodium hydroxide solution.


$2Al + 2NaOH + 6H _2O \rightarrow  2Na[Al(OH) _4] + 3H _2\uparrow$


Hence, the correct option is $\text{C}$

Soft metals which can be cut with a knife is/are :

  1. lithium

  2. potassium

  3. gold

  4. both A and B


Correct Option: D
Explanation:

Metals like lithium, sodium and potassium can be cut with a knife because their melting point is low as compared to other alkali metals. 


Although alkaline earth metals with the exception of magnesium and beryllium can be also cut with a knife.

Hence the correct option is D.

Articles made of metals produce ringing sound when struck hard.

  1. True

  2. False


Correct Option: A
Explanation:

Sonority is the property of a metal in producing a characteristic resonant sound when struck. All metals are highly sonorous and sonority varies with metals.

Metals are generally hard. Which of the following metals is an exception and can be cut with a knife?

  1. Iron

  2. Sodium

  3. Gold

  4. Magnesium


Correct Option: B
Explanation:

Metals, in general, are hard as solids at room temperature but sodium is a metal that is exceptional. 


Sodium is stored in kerosene and is soft that it can be cut with a knife.

Hence the correct option is B.

A metal M which is one of the best conductor of heat and electricity used in making electric wires is found in the nature as sulphide ore, $M _2S$. Name the metal M.

  1. Cu

  2. Al

  3. Fe

  4. Ag


Correct Option: A
Explanation:

Metal 'M' is copper which is one of the best conductor of heat and electricity used in making electric wires is found in nature as sulphide ore $(Cu _2S).$

Hence option A is correct answer.

Metals generally have ______ number of electron(s) in their valence shell.

  1. 1, 2, or 3

  2. 7, 8 or 9

  3. 10, 11, or 12

  4. 20, 30, or 40


Correct Option: A
Explanation:

Alkali and alkaline earth metals have valence electrons as 1 and 2 respectively. In general, elements with 1-3 valence electrons can be metal except for hydrogen and helium (nonmetal) and Boron (metalloid). Also, transition elements have 2 valence electrons but since they can utilize d-orbital for bonding, therefore can have variable oxidation states.
Therefore in general  1-3 valence electrons can be meta.
Hence, option $A$ is correct.

Metals are usually hard. Hence metals are strong and can withstand heavy loads over them. Due to this property, they are difficult to cut and can be used in the construction of heavy machines, building etc.
On the other hand, non-metals are usually brittle. On hammering them they break into small pieces converting themselves into a fine powder.


Thus an element that is relatively strong is relatively :

  1. Brittle

  2. Malleable

  3. Hard

  4. Ductile


Correct Option: C
Explanation:

Element that is relatively strong have strong force of attraction and difficult to break and are considered to be relatively hard.