Class 10 Science

How does the metallic character of elements vary on moving from
List any three observations which posed a challenge to Mendeleev’s Periodic Law
Write the essential function performed by ozone at the higher levels of the Earth’s atmosphere
What are solar cells ? Explain the structure of solar panel
A 10 cm tall object is placed perpendicular to the principal axis
A student holding a mirror in his hand, directed the reflecting surface of the mirror
What is carpel ? Write the function of its various parts
Where do the substances in plants reach as a result of translocation
What is translocation, Why is it essential for plants
What is transpiration ? List its two functions
List in tabular form three distinguishing features between autotrophic nutrition and heterotrophic nutrition
What is a homologous series of carbon compounds
What are amphoteric oxides
While diluting an acid, why is it recommended that the acid should be added to water
On heating blue coloured powder of copper (II) nitrate in a boiling tube
Silver articles become black when kept in open for some time
Metals like sodium and potassium are stored under oil
Platinum, gold and silver are used to make jewellery
Why are the heating elements of electric toasters and electric irons
Name two industries based on forest produce
In the Modern Periodic Table, a zigzag line separates metals from non-metals
What happens when food materials containing fats and oils are left
If vast tracts of forests are cleared and a single species of plant is cultivated
There are different forms of energy and one form of energy
List two advantages of adopting the atomic number of an element as the basis of classification
Write the electronic configurations of the elements X (atomic number 13) and Y (atomic number 20)
Differentiate between biodegradable and non-biodegradable substances with the help of one example each
Speciation
Taking the example of an element of atomic number 16
Two elements P and Q belong to the same period of the modern periodic table and are in Group-1 and Group-2 respectively
The modern periodic table has been evolved through the early attempts
State Modern periodic law
Name the scientist who first of all showed that atomic number of an element