lt 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?
Gold is a noble metal it does not react with the gases present in the atmosphere.
Silver reacts with some gases like hydrogen sulphide and loses its shine in moist air.
Related Articles
- One day Reeta went to a jeweller’s shop with her mother. Her mother gave an old gold jewellery to goldsmith to polish. Next day when they brought the jewellery back, they found that there was a slight loss in its weight. Can you suggest a reason for the loss in weight?
- One day Reeta went to a jeweller’s shop with her mother. Her mother gave an old gold jewellery to the goldsmith to polish. Next day when they brought the jewellery back, they found that there was a slight loss in its weight. Can you suggest a reason for the loss in weight?
- Kristin received a CD player for her birthday. She bought 3 CDs and received 5 others as gifts. What fraction of her total CDs did she buy and what fraction did she receive as gifts?
- Explain why, the surface of some metals acquires a dull appearance when exposed to air for a long time.
- Madhu gave two fifth of a chocolate to her friend and one fourth or to another friend the quantity of chocolate left with her is
- Explain the difference between the physical and chemical properties of metals and non-metals with the help of a table.
- Which of the two metals is more reactive: copper or silver?
- Paheli bought a statue made up of copper. To her surprise, it acquired a dull green coating after a couple of months. Explain the reason.
- Sherin divided one roti into two equal parts and gave one part or $\frac{1}{2}$ of the roti to her daughter. Find the remaining part of roti with her ?
- Paheli was writing a letter to her friend. She crumpled and threw the first draft of her letter on the floor as it had become untidy. Similarly, she crumpled and threw 6 more papers on the ground. In the end, she picked them up and put them in a polythene bag and threw it on the road outside her house. Do you think Paheli’s actions were responsible? What would you have done if you were in her place?
- While playing tug of war, Preeti felt that the rope was slipping through her hands. Suggest a way out for her to prevent this."
- lt was Paheli’s birthday, her brother Simba was helping her to decorate the house for the birthday party and their parents were also busy making other arrangements. Following were the activities going on at Paheli’s home:(i) Simba blew balloons and put them on the wall.(ii) Some of the balloons got burst.(iii) Paheli cut colourful strips of paper and put them on the wall with the help of tape.(iv) She also made some flowers by origami (paper folding) to decorate the house.(v) Her father made dough balls.(vi) Mother rolled the dough balls to make puries.(vii) Mother heated oil in a pan.(viii) Father fried the puries in hot oil.Identify the activities at Paheli’s home as those that can be reversed and those which cannot be reversed.
- Kanika was given her pocket money on Jan \( 1^{\text {st }}, 2008 \). She puts Re 1 on Day 1 , Rs 2 on Day 2, Rs 3 on Day 3 , and continued doing so till the end of the month, from this money into her piggy bank. She also spent Rs 204 of her pocket money, and found that at the end of the month she still had Rs 100 with her. How much was her pocket money for the month?
- Radhika’s mother gave her Rs. 10.50 and her father gave her Rs. 15.80, find the total amount given to Radhika by the parents.
- Why was silver replaced by gold to control the Indian economy?
Kickstart Your Career
Get certified by completing the course
Get Started