Tag: what is inside atom

Questions Related to what is inside atom

$ _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

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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. $10^2 kg/cc$

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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

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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. $16-8$.

The ratio of neutrons in ${O}^{16}$ and ${O}^{18}$ is

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

  1. $8 : 10$

  2. $4 : 5$

  3. $9 : 8$

  4. $1 : 1$

Show answer
Correct Option: A,B
Explanation:

 The ratio of neutrons in $\displaystyle {O}^{16}$ and $\displaystyle {O}^{18}$ is $\displaystyle 4 : 5 \text { or } 8 : 10$
Number of neutrons in $\displaystyle {O}^{16} = 16-8=8$
Number of neutrons in $\displaystyle {O}^{18}=18-8=10$