List of top Science Questions

In plants, waste products like resin and gum are stored in:
Select the hydrocarbon from the following which contains one C$\equiv$C triple bond and one C–C single bond:
The acid present in nettle leaves is:
A few drops of turmeric solution are added to a colorless liquid. If the liquid turns red in color, the liquid could be:
Write the name of the part of the human female reproductive system where the following functions take place:
Maturation of ovum
Fertilization of ovum with sperm
Zygote formation
Identify the labeled parts A, B, C, and D in the given diagram of a flower.
What happens when:
The ovum is fertilized?
The ovum is not fertilized?
Explain each with an example:
(1) Unisexual flower
(2) Bisexual flower
"Pollination can occur without fertilization, but fertilization cannot occur without pollination." Justify this statement.
Why is a basic solution used to treat a bee sting?
Write the name and formula of a gas whose solution is basic.
Name the acids present in:
Tomato
Tamarind (imli)
Give one example each of (i) a natural ecosystem and (ii) an artificial (man-made) ecosystem.
Define crystalline water.
A certain aqueous solution turns blue litmus red. On adding an excess of which of the following solutions will this change be reversed?
Lemon juice
Magnesium hydroxide
Vinegar
Calcium sulphate
Which of the following will turn phenolphthalein pink?
CH$_3$COOH
Ca(OH)$_2$
HCl
NaOH
Differentiate between a solenoid and a circular coil.
Even though the liver has no digestive enzymes, it plays an important role in digestion. Explain.
(i) Why do the members of a homologous series show similar chemical properties?
(ii) What is the difference in number of carbon and hydrogen atoms between two consecutive members of a homologous series?
Give one example each of (i) Alkanes, (ii) Alcohols, (iii) Aldehydes.
(a) Write the names of glands located in the stomach and list the digestive enzymes secreted by them.
Explain how a solenoid can be made in a school lab.
(i) Explain why carbon forms strong bonds with other elements.
(ii) Why do covalent compounds have low melting and boiling points?
(iii) Draw electron dot structure of chlorine (atomic number 17).
Write one use of a strong magnetic field produced inside a solenoid.
State Fleming’s Left-Hand Rule.
Based on the given data, determine the image position formed by a spherical mirror: \[ u = -20\, \text{cm}, f = -15\, \text{cm} \]