Below are the 30 Most repeated Chemistry MCQs for test 2024:
Structure of Atoms Important MCQs:
1➤ Which one of the following resulted in the discovery of proton?
ⓑ Canal rays
ⓒ X-rays
ⓓ Alpha rays.
2➤ Which one of the following is the most penetrating?
ⓑ Electrons
ⓒ Neutrons
ⓓ Alpha particles
3➤ The concept of orbit was used by
ⓑ Rutherford
ⓒ Bohr
ⓓ Planck
4➤ Which one of the following shell consists of three subshells?
ⓑ N shell
ⓒ L shell.
ⓓ M shell
5➤ Which radioisotope is used for the diagnosis of tumor in the body?
ⓑ Iodine-131
ⓒ Strontium-90
ⓓ Phosphorus-30
6➤ When U-235 breaks up, it produces:
ⓑ Neutrons
ⓒ Protons
ⓓ Nothing
7➤ The p subshell has:
ⓑ Two orbitals
ⓒ Three orbitals
ⓓ Four orbitals
8➤ Deuterium is used to make:
ⓑ Heavy water
ⓒ Soft water
ⓓ Hard water
9➤ he isotope C-12 is present in abundance of:
ⓑ 97.6%
ⓒ 99.7%
ⓓ None of these
10➤ Who discovered the proton:
ⓑ J. J. Thomson
ⓒ Neil Bohr
ⓓ Ruther Ford
11➤ Concept of atoms was presented by:
ⓑ Muslim Philosophers
ⓒ Latin Philosophers
ⓓ Modern Philosophers
12➤ What does the word "atom" mean?
ⓑ Indivisible
ⓒ Invisible
ⓓ Invincible
13➤ In the beginning of 19th century, John Dalton proposed an atomic theory about the:
ⓑ Size of atom
ⓒ Mass of atom
ⓓ Reactivity of atom
14➤ Goldstein, J.J. Thomson, Rutherford and Bohr proved that the atom is:
ⓑ Indivisible
ⓒ Stable
ⓓ Unstable
15➤ Who discovered protons?
ⓑ J.J. Thomson
ⓒ Bohr
ⓓ John Dalton
16➤ In 1897, discovered by: electrons were
ⓑ J.J. Thomson
ⓒ Newton
ⓓ Bohr
17➤ According to plum pudding model, an atom is solid structure of positive charge with ---------- particles stuck inside it.
ⓑ Negative
ⓒ Free
ⓓ Neutral
18➤ The rays which are emitted by cathode in a discharge tube when high voltage current is passed through it at a low pressure are called:
ⓑ Canal rays
ⓒ Cathode rays
ⓓ Neutrons
19➤ Which of the following element has no neutron in its nucleus?
ⓑ Nitrogen
ⓒ Carbon
ⓓ Hydrogen
20➤ According to Rutherford's experiment, most space of an atom is empty because most particles --------- the gold fall undeflected.
ⓑ Settled in
ⓒ Bounced back
ⓓ Turned obliquely
21➤ According to Bohr, energy of an electron is:
ⓑ Quantized
ⓒ Increased
ⓓ Unchanged
22➤ When an electron jumps from a lower to a higher orbit, it --------- energy.
ⓑ Decreases
ⓒ Absorbs
ⓓ Loses
23➤ What is constant? value of Planck's constant ?
ⓑ 6.63×10-34JS
ⓒ 6.11×10-28Js
ⓓ 6.46x10-24J5
24➤ According to Bohr, spectrum of an atom is:
ⓑ Broken spectrum
ⓒ Continuous spectrum
ⓓ Fixed spectrum
25➤ Which letter is used to represent 1st energy level which is closest to the nucleus?
ⓑ L
ⓒ M
ⓓ N
26➤ Which alphabets are used to represent sub shells?
ⓑ w,x,y,z
ⓒ g,h,i,j
ⓓ s,p,d,f
27➤ Maximum capacity of a shell to accommodate electrons is given by the formula:
ⓑ n²
ⓒ 2n²
ⓓ 3n²
28➤ The atomic number of oxygen is 8. What will be its configuration? electronic
ⓑ 1s², 2s², 2p²
ⓒ 1s², 2s², 2p
ⓓ 1s², 2s², 2p5
29➤ An electron first fills 2p orbital before 3s orbital because 2p orbital has:
ⓑ Lower energy level
ⓒ More number of electrons
ⓓ Greater distance from nucleus
30➤ An element has 5 electrons in M shell what will be its atomic number?
ⓑ 11
ⓒ 15
ⓓ 18
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