In a neutral ion, the number of protons would be equal to the number of electrons. You get a positive or negative charge when electrons are lost or gained.
Example: 12/6 C1-
There are 6 protons, 6 neutrons, and 7 electrons.
Answer:
0.50 g/mL
Explanation:
Formula of Density,
D = mass / volume
Mass = 12.2 g
Volume = 54.4 mL - 30.0 mL = 24.4 mL
Putting values,
D = 12.2 g / 24.4 mL
D = 0.50 g/mL
Answer is (3) both mass number and atomic number.
The notation is ₅₅¹³⁷Cs. The Cs represents the chemical symbol of Caesium element. The subscript number at the left hand side of the symbol indicates the atomic number. Hence, atomic number of Cs is 55. The superscript number at the left hand side of the symbol shows the mass number. Hence, the mass number of the Cs is 137.
