As we go down a group the distance between the nucleus and valence electrons increases, while the charges involved stay the same. This obviously has the effect of weakening the force of attraction and the valence electron is held with less force.
Why does the force of attraction between the nucleus and electrons decrease down a group?
As you go down a group, the nuclear charge decreases because the valence electrons move further away from the nucleus depleating the force of attraction between the nucleus and the electrons.
Does force of attraction decrease across a period?
With a larger distance between the negatively-charged electron and the positively-charged nucleus, the force of attraction is relatively weaker. Therefore, electron affinity decreases. Moving from left to right across a period, atoms become smaller as the forces of attraction become stronger.
Why does the force of attraction increase across a period?
Across the period the Atomic radii decreases
The electron repulsion is balanced by the nuclear charge attractions, and as the nuclear charge gets larger, so the electrons get closer together. The net attractive electrostatic attraction is increased as the nuclear charge increases.
How and why does the force of attraction between the nucleus and the valence electrons change as you move across a period?
The net force of attraction between the nucleus and the valence electron in an atom increase as you move across a period from left to right. As you move across a period, the valence electrons in the atom experience a stronger pull toward the nucleus. DECREASES.
Why does electron affinity decrease down a group?
Electron affinity decreases down the groups and from right to left across the periods on the periodic table because the electrons are placed in a higher energy level far from the nucleus, thus a decrease from its pull.
When effective nuclear charge decreases what happens to the attraction between the nucleus and the electrons?
1). Hence the electrons will cancel a portion of the positive charge of the nucleus and thereby decrease the attractive interaction between it and the electron farther away. As a result, the electron farther away experiences an effective nuclear charge (Zeff) that is less than the actual nuclear charge Z.
Does shielding increase down a group?
Shielding increases DOWN a Group because the nuclear core is farther removed from the valence electrons.
Why does reactivity decrease across a period?
Period – reactivity decreases as you go from left to right across a period. The farther to the left and down the periodic chart you go, the easier it is for electrons to be given or taken away, resulting in higher reactivity. … Group – reactivity decreases as you go down the group.
Does Zeff increase or decrease down a group?
The effective nuclear charge, Zeff, increases down a group which draws electrons closer towards the nucleus, decreasing atomic radius.