Tag: chemistry

Questions Related to chemistry

The triad of nuclei that is isotonic is :

chemistry what is inside atom neutrons discovery of neutrons structure of atoms

  1. $^{14} _6C,\,^{15} _7N,\, ^{17} _9F$

  2. $^{12} _6C,\,^{14} _7N,\, ^{19} _9F$

  3. $^{14} _6C,\,^{14} _7N,\, ^{17} _9F$

  4. $^{14} _6C,\,^{14} _7N,\, ^{19} _9F$

Show answer
Correct Option: A
Explanation:

The triad of nuclei that is isotonic is  $^{14} _6C,\,^{15} _7N,\, ^{17} _9F$.
Number of neutrons are
$C -14-6=8$
$N-15-7=8$
$F-17-9=8$

The atoms of different elements having the same number of neutrons are known as :

chemistry what is inside atom neutrons discovery of neutrons structure of atoms

  1. isobars

  2. isomers

  3. isotones

  4. isotopes

Show answer
Correct Option: C
Explanation:

Two nuclides are isotones if they have same neutron number but different proton number e.g. $boron-12$ and $carbon-13$ both contain 7 neutrons so they are $isotones$.

The nuclides $^{40} _{18}Ar$ and $^{41} _{19}K$ are :

chemistry what is inside atom neutrons discovery of neutrons structure of atoms

  1. isotopes

  2. isobars

  3. isotones

  4. none of these

Show answer
Correct Option: C
Explanation:

The two or more species of atoms or nuclei that have the same number of neutrons are called as isotones.


The nuclides $^{40} _{18}Ar$ and $^{41} _{19}K$ are isotones. Because they have the same number of neutron.

So, the correct option is $C$

$ _7N^{15}$ and $ _8O^{16}$ are a pair of :

chemistry what is inside atom neutrons discovery of neutrons structure of atoms

  1. isotopes

  2. isobars

  3. isotones

  4. none of them

Show answer
Correct Option: C
Explanation:

Two nuclides are isotones if they have the very same neutron number but different proton number.

Density of neutron is of the order of :

chemistry what is inside atom neutrons discovery of neutrons structure of atoms

  1. $10^3 kg/cc$

  2. $10^6 kg/cc$

  3. $10^{12} kg/cc$

  4. $10^2 kg/cc$

Show answer
Correct Option: C
Explanation:

$Atomic\quad radius\quad of\quad neutron\quad =\quad { 10 }^{ -13 }cm\ mass\quad of\quad neutron\quad =\quad 1.6749\times { 10 }^{ -27 }kg\ density\quad of\quad neutron\quad =\quad \dfrac { Mass }{ Volume } =\quad { 10 }^{ 12 }\quad kg/cc$

Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?

chemistry what is inside atom neutrons discovery of neutrons structure of atoms

  1. 4

  2. 2

  3. 8

  4. 6

Show answer
Correct Option: B
Explanation:

Helium has 2 neutrons. The mass of an atom is given by the sum of the masses of protons and neutrons present in the nucleus. Since, the number of protons present in helium is 2 and given mass is 4. Therefore, the number of neutrons will be equal to $2$ i.e. $4-2.$

Carbon has six protons and six neutrons in its nucleus. What is the atomic mass of carbon?

chemistry what is inside atom neutrons discovery of neutrons structure of atoms

  1. 4

  2. 12

  3. 8

  4. 6

Show answer
Correct Option: B
Explanation:

The atomic mass of carbon is $12$. The mass of an atom is given by the sum of the masses of protons and neutrons present in the nucleus. Since, the number of protons and neutrons present in carbon is $6$.
Therefore, the atomic mass of carbon is $12$ i.e. $6 + 6=12$.

Oxygen atom has an atomic mass of 16 u and eight neutrons in its nucleus. What is its atomic number?

chemistry what is inside atom neutrons discovery of neutrons structure of atoms

  1. 4

  2. 12

  3. 8

  4. 6

Show answer
Correct Option: C
Explanation:

The atomic number of oxygen is 8. The mass of an atom is given by the sum of the masses of protons and neutrons present in the nucleus. Also, atomic number is the number of protons present in the nucleus. Since, the number of neutrons present in oxygen is 8 and given mass is 16. Therefore, the number of neutrons will be equal to $8$ i.e. $16-8$.

Which of the following particle has mass closest to the mass of a proton?

chemistry structure of the atom neutrons discovery of neutrons structure of atoms

  1. Neutron

  2. Hydrogen molecule

  3. Alpha particle

  4. Positron

  5. Electron

Show answer
Correct Option: A
Explanation:

Neutron has closest mass to a proton. The mass of proton and neutron are 1.0073 amu and 1.0087 amu respectively. Mass of electron is much lower than that of proton and neutron

Statement 1: Neutrons and protons are classified as nucleons.
Statement 2: Neutrons and protons are both located in the principal energy levels of the atom.

chemistry structure of the atom neutrons discovery of neutrons structure of atoms

  1. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.

  2. Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1.

  3. Statement 1 is correct but Statement 2 is not correct.

  4. Statement 1 is not correct but Statement 2 is correct.

  5. Both the Statement 1 and Statement 2 are not correct.

Show answer
Correct Option: C
Explanation:
A nucleon is a collective name for two important subatomic particles: neutrons and protons. A nucleon is one of either of the two types of subatomic particles (neutrons and protons) which are located in the nucleus of atoms.
electrons are located in the principal energy levels of the atoms so statement 2 is not correct because neutron and proton stay in the nucleus of an atom.