2. Fill in the blanks : [1 mark each]
(1) On heating ice, it gets converted into
water
( 2 ) Iron
on heating
(3) When cold water is poured over a hot iron rim, it
( 4 ) If we sharpen a pencil again and again, its
(5) The transformation of a solid substance into liquid is a / an
change.
decreases
Answers
Answer:
4) If we sharpen a pencil again and again, its
Answer:
(1) fusion
(2) Three reasons come readily to mind; there are more, of course.
- To make it soft enough to be worked into new shape (forging).
- To provide a hot, heavy surface for de-wrinkling clothes. (The heat temporarily plasticizes the fabric’s fibers, allowing them to be pressed smooth by the clothes iron.)
- To demagnetize it if it has become unwantedly magnetized.
(3) The rim is made deliberately slightly smaller and when it is cold it doesn't fit. So it is heated and as a result it expands enough to then fit onto the wheel when it cools it shrinks and tightens up the entire structure of the wheel. Cooling the red hot tyre with water quickly stops it burning the wooden wheel.
(4) length
(5) The process of a solid becoming a liquid is called melting. (an older term that you may see sometimes is fusion). The opposite process, a liquid becoming a solid, is called solidification. For any pure substance, the temperature at which melting occurs—known as the melting point—is a characteristic of that substance.