Answer the following questions
1. On a cold wintery day, you burn firewood to keep yourself warm. Th
firewood undergoes a change in state.
a. Name the change in state of matter that you see.
b. Explain answer (a) with regard to shape and volume based on th
arrangement of particles
2. Leakage of Liquid Petroleum Gas (LPG) can be detected by a person
from a distance. In reference to this process, write two applications of i
in our day to day life,
3. Look around and write down the name and symbol of elements that are
present in your classroom.
Imagine that you are a particle of water. Describe your experiences
during the following happenings: evaporating, diffusion, and freezing.
is an element. Identify the element and write down its symbol,
mass number and atomic number.
Answers
Answer: 1.a. Burning of wood is a chemical change as new substances which cannot be changed back (e.g. carbon dioxide) are formed. For example, if wood is burned in a fireplace, there is not wood anymore but ash.
b. In physical changes no new materials are formed and the particles do not change apart from gaining or losing energy. Particles stay the same unless there is a chemical change whether the matter is solid, liquid or gas. Only their arrangement, energy and movement changes.
2. When a gas leak is suspected, extinguish all flames, incense sticks, etc.
Close the LPG regulator and put the safety cap on the cylinder.
Don t light matches (or a lighter).
Do not switch on/off any electrical switches or appliances.
3. (Can't answer this one)
Answer:1.ans chemical change
Explanation: