Metals

Q. (a) Give reason: A frying pan is made up of steel but its handle is made up of wood.​

Q. It was Paheli’s birthday. Her grandmother gave her two gifts made of metals, one old dull silver spoon and a pair of lustrous gold earrings. She was surprised to see the difference in the appearance of the two metals. Can you explain the reason for this difference?​

Q. Explain in brief the importance of chemistry in communication devices.

Q.

Match the following:

$\begin{array}{cccc}\text{(i)}& \text{Oxygen}& \text{(A)}& \text{Metal}\\ \text{(ii)}& \text{Sodium}& \text{(B)}& \text{Metalloid}\\ \text{(iii)}& \text{2ex Boron}& \text{(C)}& \text{Non-metal}\\ \text{(iv)}& \text{Gold}& & \\ \text{(v)}& \text{Carbon dioxide}& & \end{array}$

The correct pairs are:-

1. (ii, v) – C, (i, iv) - B, (iii) - A

2. (i, iv) – C, (ii, v) - B, (iii) - A

3. (i, v) – C, (ii, iv) - B, (iii) - A

4. (i, v) – C, (iii) - B, (ii, iv) - A

Q. Select natural and man made from the following list:​

Wood , plastic , Silk , medicines , detergent , coal , water , ceramic , cotton , glass , nylon , fruits ​

Q.

Mention the similarities between copper iron and aluminium

Q.

Write the atomicity of metals and non-metals.

Q.

Name a rare gas other than neon krypton and xenon.

Q.

Which of the following is/are metalloid?

1. Al

2. Both Si&Al

3. Ga

4. Si

Q. Which pair of substances among the following would float in a tumbler half filled with water?

1. Cotton thread, thermocol​
2. Feather, plastic ball​
3. Pin, oil drops​
4. Rubber band, coin​

Q.

Which of the kind of elements gives harmful radiation?

1. Metal

2. Non-metal

3. Radioactive element

4. Normal element

Q. Which materials can be used to make the handle of a frying pan?

1. Copper
2. Wood
3. Iron
4. Plastic

Q.

Find the odd one out of the following ​substances based on use.​

1. 
2. 
3. 
4. 

Q. State if the following statement is true or false:
The metal Potassium (K) is so soft that it can be cut with a knife.

1. False
2. True

Q. Which of the following is a preventive method for corrosion?

1. Hammering
2. Heating
3. Galvanisation
4. Cleaning with water

Q. Materials change their physical state on heating up or cooling down.

1. False
2. True

Q. An element is sonorous and highly ductile. Under which category would you classify this element? What other characteristics do you expect the element to possess?

Q. Give two examples for each of the following:
(a) metals
(b) non-metals
(c) metalloids

Q.

Statement given below is incorrect. Write the correct statement.

Elements can be divided into metals, non-metals and gases.

Q.

Identify the error in the given statements. Circle the incorrect word and write the correct word in the blank.

Noble gases show some properties of metals and some properties of non-metals.

Q. Materials change their physical state on heating up or cooling down.

1. False
2. True

Q. Kiran bought a small statue which turned green after few months. What will be the reason for the colour change?

1. Corrosion of iron
2. Corrosion of tin
3. Corrosion of copper
4. Corrosion of silver

Q. In the previous video, there was a peculiar material which was not burning along with the wooden sticks but was changing colour, melting on prolonged heating and was able to change shape upon beating. What can that material probably be?

1. Wood
2. Metal
3. Stone
4. Ceramic

Q. Observe the table and identify metals and non-metals. Select the correct option.
$\begin{array}{ccc}\text{Sl.No}& \text{Set-1}& \text{Set-2}\\ \text{1.}& \text{Sodium(Na)}& \text{Oxygen(O)}\\ \text{2.}& \text{Magnesium(Mg)}& \text{Chlorine(Cl)}\\ \text{3.}& \text{Iron(Fe)}& \text{Helium(He)}\\ \text{4.}& \text{Gold(Au)}& \text{Sulphur(S)}\\ \text{5.}& \text{Calcium(Ca)}& \text{Carbon(C)}\end{array}$

1. Both Sets - 1 & 2 are Metals
2. Both Sets - 1 & 2 are Non-metals
3. Set - 1 (Non-metals) and Set - 2 (Metals)
4. Set - 1 (Metals) and Set - 2 (Nonmetals)

Q. A peculiar material (A) doesn't burn like wooden sticks but changes color when heated, melts upon prolonged heating and is able to change shape upon beating. A can be ______

1. Ceramic
2. Metal
3. Sulphur
4. Stone

Q.

why are bells made up of metal and not of wood?

Q. only metal liquid at room temperature

Q. Metals are good conductors of ______and ________.

1. heat
2. electricity
3. energy
4. water

Q. (a) Chalk and aluminium foil usually look different from each other. Give a property by which we can prove that these materials are different. [1 mark]

(b) Metals have lustre (shine). Give a reason why some metal articles become dull and lose their shine after some time. [1 mark]

(c) Mixtures of red chilli powder in water, butter in water, petrol in water, and vinegar in water were given to Radha, Sudha, Sofia and Raveena, respectively. Whose mixture is in solution form?​ [1 mark]

(d) During the summer holidays, a group of children collected a small thermocol box and a piece of sugar candy (mishri) and tried to group them on the basis of properties such as floatation and solubility in water by making a table. What would that table look like? [2 marks]

Q. The melting point of gallium is ${30}^{\circ }\text{C}$. Then its freezing point will be ____${}^{\circ }\text{C}$.

1. 30