Chemistry: Isotopes, Average Atomic Mass, Reaction, Ions, Effective Nuclear Charge..

Isotopes

Same number of protons and electrons, different number of neutrons. Changing neutrons does not change the identity.

Unstable Isotopes

It will undergo radioactive decay. It will remove parts of itself thereby losing mass until it becomes stable, and once it is stable, it will no longer need to decay. (Half life is a measurement of the rate of radioactive decay)

Carbon Dating

It is the method used to determine the age of organic materials. It relies on the decay of radioactive isotopes, like carbon.

Column/Groups

Vertical

Row/Period

Horizontal

Chemical Bond

An electrostatic force of attraction that holds atoms together in a molecule. Atoms form it with other atoms to reach a more stable state.

Stable State

An atom would need a complete valence orbital of electrons, and atoms w/ greater stability have less energy.

Ionic Bond

Atoms transfer electrons to have a complete valence shell. Atoms gain or lose electrons to form ion.s Ionic compounds are held together by the electrostatic attraction of the ions.

Ionic Compound

Is a compound composed of ions held together by ionic bond.

Cations

Metals form it by losing an electron.

Anion

Non-metals form it by gaining an electron

Effective Nuclear Charge

is defined as the net positive charge pulling these electrons towards the nucleus. The stronger the pull on the outermost electrons (valence electrons) towards the nucleus, the higher the thing

Shielding Effect

Is when electrons in full inner shell repel electrons in outer shells, preventing them from feeling a strong attraction.

Metals Reactivity.

They react by losing valence electrons. As there are more energy levels, it is further from the nucleus, which means less attraction force of the valence electrons, more readily removed.

Non-metals reactivity

Greater for Zeff have a greater pull on valence electrons from neighbouring atoms. Those elements with a fewer energy levels have the nucleus at a shorter distance to neighbouring valence electrons, with more attractive force pulling the electrons, so they more readily gain electrons.

Ionic Compound Chemical Formula

Second term: etc. ox -ide