Answer:
the first one to the third box
the second one to the fourth box
the third one to second box
and the fourth one to the first box
Explanation:
Answer: Option (c) is the correct answer.
Explanation:
Wood is a mixture of different substances. Primarily it consists of cellulose, lignin, water etc.
When we heat wood then all these substance oxidize into the atmosphere even before they could melt.
Whereas iron, sodium chloride and ethanol all are the substances which can melt at any temperature.
Thus, we can conclude that out of the given options, wood, a mixture of different substances is a material that does not melt at any temperature.
The answer will be physical change
Answer:
When chlorine and bromine atoms come into contact with ozone in the stratosphere, they destroy ozone molecules.
Explanation:
Answer:
f = 80 flutter/ second
T= 0.0125 sec
Explanation:
Given data:
Fluttering of wings = 4800 time per minute
Frequency of wings = ?
Period for one wing in sec = ?
Solution:
There are 60 seconds in one minute, thus frequency of wings
4800/60 = 80 flutter per second
Period:
T = 1/f
T = 1/80
T= 0.0125 sec
