D. Both are made of the same number of atoms. 3. Which of the following scientists added negatively-charged particles to the model of the atom? A. Niels Bohr B. John Dalton C. Ernest Rutherford D. J. J. Thomson 4. Calcium is an element. What is the smallest particle of calcium that has all the chemical properties of calcium?

D. J. J. Thomson

An atom of calcium

Explanation:

J.J. Thomson while carrying out his experiment on the gas discharge tube discovered electrons. He called them cathode rays.

He observed from his experiment that these rays have the following properties;

From his experiment, he proposed the plum pudding model of the atom where an atom is made up essentially of electrons.

B. The smallest particle of calcium that has all the chemical properties of calcium is an atom of calcium.

It is upon these unit of calcium that the substance calcium is formed. An atom of calcium will show the same properties as a block of calcium.