What do these have in common? 20Ne 19F- 24Mg2+

Question

Can you please explain step by step. thank you!

Answer 1

Hmm...only thing I'm finding is that there's the same number of electrons in each isotope.

This is, however, assuming that you mean to write ²⁰Ne, ¹⁹F^-, and ²⁴Mg²⁺, reflecting their isotopes.

Let's get a tally of the number of electrons, neutrons, and protons for these three isotopes:

 

²⁰Ne

10 protons, given by atomic number (look at your periodic table)

10 electrons, given neutral charge (meaning protons equal electrons)

10 neutrons, given neutrons and protons must add to 20 (given by the isotope number)

 

¹⁹F^-

9 protons, given by atomic number

10 electrons, given by negative one charge that ADDS an electron (electrons are negatively charged, yes this is annoying I'm so sorry)

10 neutrons, given that the protons and neutrons must add to 19

 

²⁴Mg²⁺

12 protons, given by atomic number

10 electrons, given by plus two charge TAKING AWAY two electrons

12 neutrons, given that neutrons and protons must add to 24

 

The only thing I'm noticing is that the electrons are all equal- every one adds to 10, and all of them therefore have 1s²2s²2p⁶ orbital notation (disregard orbital notation if that is irrelevant).