forces on electrons

As we go across a period, from element to element (e.g. Li→Be→B→C→...),the nuclear charge...

increases by 1

As we go down a group from element to element (e.g. Li→Na→K→Rb...), the nuclear charge...

increases by more than 1

Nuclear charge is the...

the collective charge of all the protons in a nucleus

As an electron’s distance from the nucleus increases, the force it experiences...

decreases

The third shell can contain a maximum of how many electrons?

18

How do we represent the electrons in a scandium atom?

How do we represent the electrons in a copper atom?

The higher an atom’s nuclear charge...

the closer each shell is to the nucleus

Across a period, the distance between the nucleus and outer electrons...

decreases And that’s because…

nuclear charge increases across a period

Select the two main factors which affect the distance between the nucleus and outer electrons

nuclear charge

which shell the outer electrons are in

Down a group, the distance between the nucleus and outer electrons...

increases

And that’s because…electrons occupy a new shell that’s further from the nucleus

Instead of calculating all the individual repulsions between electrons in an atom, we assume that each electron...

shields some nuclear charge from other electrons

An electron in a shell closer to the nucleus...

shields the charge of one proton

An electron in the same shell...

shields a small amount of charge

Electron A will shield…

Some charge (much less than the charge of 1 proton) from electron B

Electron A will shield…

Some charge (much less than the charge of 1 proton) from electron B

As we move down a group, from beryllium to calcium what happens to inner and outer electrons?…

the number of inner electrons increases

the number of outer electrons stays the same

Across a period the amount of shielding on outer electrons...

stays roughly the same.

Down a group the amount of shielding on outer electrons…

increases significantly.

Which electron experiences more shielding?

Electron B

Which electron experiences more shielding?

Electron A

elect the 3 key factors which affect an electron’s attraction to the nucleus.

shielding

nuclear charge

distance from nucleus

Across a period an outer electron’s attraction to the nucleus...

increases

what happens to nuclear charge down the group?

increases

Down a group the attraction of an outer electron to the nucleus...

decreases

In which atom do the outer electrons experience a stronger attraction to the nucleus?

An atom of helium

In which atom do the outer electron(s) experience a stronger attraction to the nucleus?

An atom of krypton