Question

1. What is meant by displacement reaction? Give an example?
2. Write an experiment to show that sound needs a medium to travel?
3. Write any two possible causes of tremors on the earth?
4. A sound wave produces 450 oscillations in 90 seconds. Find the frequency
and time period of vibration?​

Answer 1

Answer:

Ans.1- A displacement reaction is the one wherein the atom or a set of atoms is displaced by another atom in a molecule. For instance, when iron is added to a copper sulphate solution, it displaces the copper metal. A + B-C → A-C + B. The above equation exists when A is more reactive than B.

Ans.2- Bell-jar experiment demonstrates that sound needs a medium for its propagation. Take an electric bell and an air tight glass bell jar connected to a vacuum pump. Suspend the bell inside the jar, and press the switch of the bell. You will be able to hear the bell ring.

Ans.3- Earthquakes are caused mostly by rupture of geological faults but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake's point of initial rupture is called its hypocenter or focus. The epicenter is the point at ground level directly above the hypocenter.

Ans.4- .........Sorry I don't know ☹️........

Hope it helps you

Answer 2

Answer:

Ans.1- A displacement reaction is where the atom or a set of atoms is displaced by another atom in a molecule. For instance, when the iron is added to a copper sulphate solution, it displaces the copper metal. A + B-C → A-C + B. The above equation exists when A is more reactive than B.

Ans.2- Bell-jar experiment demonstrates that sound needs a medium for its propagation. Take an electric bell and an air-tight glass bell jar connected to a vacuum pump. Suspend the bell inside the jar, and press the switch. You will be able to hear the bell ring.

Ans.3- Earthquakes are caused mostly by the rupture of geological faults but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake's point of initial rupture is called its hypocenter or focus. The epicentre is the point at ground level directly above the hypocenter.

Ans.4- For 450 oscillation it takes = 90secs

For one oscillation = 90/450secs (1/5secs) = timeperiod.