1.23 Calculate the numbers of protons, neutrons and electrons in simple ions​ ​given​ ​the​ ​atomic​ ​number​ ​and​ ​mass​ ​number

Question 1

What is the atomic number?

Answer 1

Atomic number = proton number = number of protons

Question 2

What is the mass number?

Answer 2

Mass number = nucleon number = number of protons + neutrons

Question 3

How does the number of protons relate to electrons in an atom?

Answer 3

In an atom, the number of protons = number of electrons.

Question 4

How does the number of protons relate to electrons in an ion?

Answer 4

In an ion, there is a different number of electrons compared to protons.

Question 5

How do you calculate the number of electrons in an ion?

Answer 5

1. Determine the number of electrons an atom of the element would have (same as proton number).
2. Determine how many electrons have been lost or gained (using charge - -ve means electrons gained, +ve means electrons lost).
3. Calculate the number of electrons in the atom plus electrons gained or minus electrons lost.