List of top Science Questions

How many types of elements together make up the xylem tissue? Name them.
Define the term “tissue”.
What do you mean by a precipitation reaction? Explain by giving examples.
An artificial satellite is moving in a circular orbit of radius 42250 km. Calculate its speed if it takes 24 hours to revolve around the earth.
Name two metals which will displace hydrogen from dilute acids, and two metals which will not.
A ball is gently dropped from a height of \(20\) \(m\). If its velocity increases uniformly at the rate of \(10\) \(m s^{-2}\), with what velocity will it strike the ground? After what time will it strike the ground?
In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
What are amphoteric oxides? Give two examples of amphoteric oxides.
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.
A motorboat starting from rest on a lake accelerates in a straight line at a constant rate of \(3.0\) \(m s^{–2}\) for \(8.0\) \(s\). How far does the boat travel during this time?
Food cans are coated with tin and not with zinc because
What is the difference between displacement and double displacement reactions? Write equations for these reactions.
An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
Which of the following pairs will give displacement reactions?
Which of the following methods is suitable for preventing an iron frying pan from rusting?
Why is respiration considered an exothermic reaction? Explain.
What does one mean by exothermic and endothermic reactions? Give examples.
What is osmosis?
A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
How does an Amoeba obtain its food?
Where do the lipids and proteins constituting the cell membrane get synthesized?
Which organelle is known as the powerhouse of the cell? Why?
What would happen to the life of a cell if there was no Golgi apparatus?
Find the focal length of a lens of power −2.0 D. What type of lens is this?