Question

Question:Which of the following is(are) correct?
a. ⁴⁰Ca²⁺ contains 20 protons and 18 electrons.
b. Rutherford created the cathode-ray tube and was the founder of the charge-to-mass ratio of anelectron.
c. An electron is heavier than a proton.
d. The nucleus contains protons, neutrons, and electrons.

Short answer

Answer

⁴⁰Ca²⁺ contains 20 protons and 18 electrons is true.

Step-by-step solution

Subatomic particles

The subatomic particles are protons, neutrons and electrons which is present in the atoms of every element. These are present in the nucleus and the electrons are revolving around the nucleus.

40Ca2+ contains 20 protons and 18 electrons

The atomic number of calcium is 20 but atomic number and protons number are equal. The electron number can be calculated as,

$$\begin{gathered} \text{Number} \text{of} \text{electrons} \text{in} {}_{\text{20}}{}^{\text{40}}\text{Ca}^{\text{2 +}}=\text{20}-\text{2} \\ =\text{18} \text{electrons} \end{gathered}$$

The statement is true.

Rutherford created the cathode-ray tube and was the founder of the charge-to-mass ratio of an electron

J. J. Thomson discovered electrons and also find charge to mass ratio. Rutherford discovered Neutron. This is false.

An electron is heavier than a proton

The electron’s mass is $9.022\times {10}^{-31}kg$whereas proton mass is$1.67\times {10}^{-27}Kg$ The proton can be heavier than electron. This isfalse.

The nucleus contains protons, neutrons, and electrons.

The atom’s nucleus contains neutrons and protons whereas electron revolving around nucleus. This is false.