English Medium इयत्ता ९ - CBSE Question Bank Solutions for Science

Name any two laws of chemical combination.

Name the negatively charged particle present in the atoms of all the elements.

State whether the following statement is true or false :
The anode rays obtained from all the gases consist of positively charged particles called protons.

Give one major drawback of Dalton's atomic theory of matter.

Fill in the blank of the following statement :

The electron has _________ charge, the proton has _________ charge, and the neutron has _________ charge.

Why is an atom neutral inspite of the presence of charged particles in it?

Compare an electron, a proton and a neutron in respect of their relative masses and charges.

Compare an electron and a proton in respect of mass and charge.

Compare a proton and a neutron in respect of mass and charge.

State the location of electrons, protons and neutrons in an atom.

State the law of constant proportions. Give one example to illustrate this law.

State the various postulates of Dalton’s atomic theory of matter.

Which postulate of Dalton’s atomic theory can explain the law of constant proportions ?

The particle not present in an ordinary hydrogen atom is :

The atomic theory of matter was proposed by :

Which of the following statement is always correct?

The law of constant proportions was given by :

In water, the proportion of oxygen and hydrogen by mass is :

In an experiment, 4.90 g of copper oxide was obtained from 3.92 g of copper. In another experiment, 4.55 g of copper oxide gave, on reduction, 3.64 g of copper. Show with the help of calculations that these figures verify the law of constant proportions.

When 5 g of calcium is burnt in 2 g of oxygen, then 7 g of calcium oxide is produced. What mass of calcium oxide will be produced when 5 g of calcium is burnt in 20 g of oxygen ? Which law of chemical combination will govern your answer ?