Chemistry

Structure of the Atom

Question:

What is the relationship between an atom containing 11 protons, 11 electrons and 11 neutrons, and another atom containing 11 protons, 11 electrons and 12 neutrons ?

Answer:

Isotopes
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Structure of the Atom

Q 1.

Write the limitations of J.J. Thomson's model of an atom.

Q 2.

What are cathode rays?

Q 3.

What were the important features of atomic model based on Rutherford's scattering experiment?

Q 4.

If A = 23 and Z = 11 for Na atom, how many protons, electrons and neutrons present in Na atom?

Q 5.

What is the mass of proton as compared to electron?

Q 6.

Who discovered electrons?

Q 7.

Fill in the blanks :
An atom has mass number 27 and atomic number 13. The atom has _________ electrons, _____ protons and _______ neutrons.

Q 8.

What are ?-particles?

Q 9.

Fill in the blanks :
__________ electrons are located in the outermost shell of an atom.

Q 10.

Who discovered protons?

Q 11.

Fill in the blanks :
The mass number of an atom is equal to the number of ________ in its nucleus.

Q 12.

Fill in the blanks :
Atoms are made up of __________, ___________ and __________.

Q 13.

Fill in the blanks :
The total number of protons and neutrons in the nucleus of an atom is called its __________.

Q 14.

What is Atomic Number? Who coined this term?

Q 15.

Fill in the blanks :
Rutherford's scattering experiment is related to to the size of ____________.

Q 16.

Fill in the blanks :
Mass of a proton is __________ times the mass of an electron.

Q 17.

Who discovered neutrons?

Q 18.

Fill in the blanks :
The maximum number of electrons that can be accommodated in K-shell are _______.

Q 19.

Fill in the blanks :
The fundamental sub-atomic particle called neutron was discovered by ___________.

Q 20.

Fill in the blanks :
The _________ of an atom is dense, small in size and is positively charged.

Q 21.

Name the fundamental particle not present in the nucleus of hydrogen atom

Q 22.

On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?

Q 23.

Write a short note on Nucleus.

Q 24.

If an atom contains one electron and one proton, will it carry any charge or not?

Q 25.

Fill in the blanks :
_______ are atoms having the same mass number but different atomic numbers.

Q 26.

Who discovered X-Rays?

Q 27.

What is ionization energy?

Q 28.

Fill in the blanks :
Nucleons are __________ and ___________.

Q 29.

What are canal rays?

Q 30.

What is mass number?

Q 31.

Fill in the blanks :
Valency is the __________ _____________ of an atom.

Q 32.

Fill in the blanks :
The fundamental particle not present in hydrogen atom is __________.

Q 33.

Draw a sketch of Bohr’s model of an atom with three shells.

Q 34.

Name the positively charged particle present in the atoms of all the element

Q 35.

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

Q 36.

Which radioactive isotope is used to determine the activity of thyroid gland ?

Q 37.

State whether the following statement is true or false :
Radioactive isotope of iodine is used for making the medicine called tincture iodine.

Q 38.

Who discovered nucleus of an atom?

Q 39.

Name the particles which actually determine the mass of an atom.

Q 40.

(a) Describe the Rutherford's model of an atom. State one drawback of Rutherford's model of the atom.
(b) The mass number of an element is 23 and it contains 11 electrons. What is the number of protons and neutrons in it ? What is the atomic number of the element ?

Q 41.

What is the electronic configuration of a hydrogen atom

Q 42.

Fill in the following blanks in respect of an atom of an element :
No.of
protons
No.of
neutrons
Mass numberAtomic
number
No.of
electrons
Valency
1112................................

Q 43.

Fill in the blanks :
In the three fundamental sub-atomic particles, _________ are negatively charged, _________ are positively charged and ____________ have no charges.

Q 44.

What is the maximum number of electrons that can go into the N shell of an atom ?

Q 45.

What is the maximum number of electrons which can be accommodated in the K shell of an atom

Q 46.

Which shell of an atom can accommodate a maximum of
(a) 8 electrons?

Q 47.

How does a proton differ from an electron ?

Q 48.

What name is given to the pair of atoms such as 147N and 157N ?

Q 49.

(a) What are radioactive isotopes ? Give two examples of radioactive isotopes.
(b)Give any two uses of radioactive isotopes.
(c)An element Z contains two naturally occurring isotopes 3517Z and 3717Z. If the average atomic mass of this element be 35.5 u, calculate the percentage of two isotopes.

Q 50.

Which part of an atom was discovered by Rutherford's alpha particle scattering experiment ?