CBSE Class 10   Class 10 Science

About the Class 10 Science category (1)
An element X on reaction with O2 forms X2O (7)
In an electrical circuit, two resistors of 2 ohm and 4 ohm are connected in series to a 6 V battery (3)
Metals towards the top of the activity series can not be obtained from their compound by reducing with carbon. Why? (3)
Life Processes (Science) the (3)
Three incandescent bulbs of 100 W each are connected in series in an electric circuit (3)
If the current I through a resistor is increased by 100% (assume that temperature (6)
How would you distinguish between baking powder and washing soda by heating? (2)
Differentiate between saturated and unsaturated hydrocarbons (5)
Explain Normal Shift with a suitable diagram (1)
State in brief the functions of the following parts of the human female reproductive system: (3)
Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid, whereas copper does not. Explain why? (3)
Why do metals not evolve hydrogen gas with nitric acid? (2)
Why is the red light used as a danger signal (5)
What are the necessary conditions to see an object ? What is light? (2)
Suggest a test to find the hardness of water and explain the procedure (2)
Which rule is violated in the electronic configuration ${{1s}^{0}}$ ${{2s}^{2}}$ ${{2p}^{4}}$? (2)
A brown substance X on heating in air forms a substance Y (3)
How does speciation take place? (2)
Five resistors are connected in a circuit as shown in figure (3)
Managenent of natural resources (1)
A white salt of lead on heating decomposes to give brown fumes and a residue is left behind. (i) Name the salt. (ii) Write the equation for the decomposition reaction (2)
Write the balanced chemical equations for the following reactions and identify the type of reaction in each case. (i) In thermite reaction, iron (III) oxide reacts with aluminium and gives molten iron and aluminium oxide (3)
How is brain in the human beings protected from injuries? (2)
How has the method of ‘artificial selection’ by humans helped in the evolution of different vegetables? (1)
Explain the ways in which evolutionary relationships can be traced (1)
What is speciation? List four factors that could lead to speciation (1)
What are fossils? How are they formed? (1)
Explain Mendel’s experiment with peas on inheritance of characters considering only one visible contrasting character (1)
Describe Darwin’s theory of evolution? (1)