English Medium इयत्ता ९ - CBSE Question Bank Solutions for Science

Cinnabar (HgS) is a prominent ore of mercury. How many grams of mercury are present in 225 g of pure HgS? Molar mass of Hg and S are 200.6 g mol^–1 and 32 g mol^–1 respectively.

Raunak took 5 moles of carbon atoms in a container and Krish also took 5 moles of sodium atoms in another container of same weight.

1. Whose container is heavier?
2. Whose container has more number of atoms?

Fill in the missing data in the Table 

The visible universe is estimated to contain 10²² stars. How many moles of stars are present in the visible universe?

Compute the difference in masses of 10³ moles each of magnesium atoms and magnesium ions.

(Mass of an electron = 9.1×10^–31 kg)

One electron is present in the outermost shell of the atom of an element X. What would be the nature and value of charge on the ion formed if this electron is removed from the outermost shell?

What are the postulates of Bohr’s model of an atom?

Find out the false sentences

Find out the correct sentence

Lysosome arises from

Why are lysosomes known as ‘suicide-bags’ of a cell?

Match the following A and B

Classify the following as physical or chemical properties

The composition of a sample of steel is 98% iron, 1.5% carbon and 0.5% other elements.

Classify the following as physical or chemical properties

Metallic sodium is soft enough to be cut with a knife.

Ice, water and water vapour look different and display different ______ properties but they are ______ the same.

Chlorine exists in two isotopic forms, \[\ce{Cl-37}\] and \[\ce{Cl-35}\] but its atomic mass is 35.5. This indicates the ratio of \[\ce{Cl-37}\] and \[\ce{Cl-35}\] is approximately

An atom having atomic mass number 13 has 7 neutrons. What is the atomic number of the atom?

Which organelle is known as the powerhouse of the cell? Why?

Name two biologically important compounds that contain both oxygen and nitrogen.

What are the two forms of oxygen found in the atmosphere?