Periodic trends: atomic radius (chapter 2)

Atomic radius:

depends on whether measured the covalent interaction and half the distance between the two nuclei

Atomic radius increases or decreases moving down a group?

increases (adding electrons)

Atomic radius increases or decreases moving across a row?

decreases

Size of atom depends on balance:

• attraction of protons and electrons

• repulsion between electrons in atom

Unlike charges attract or repel?

attract

Like charges attract or repel?

repel

q1 and q2 =

charges

r =

distance

When the charge increases what happens to the force?

increases

When distance increases what happens to the force?

decreases

Effective nuclear charge:

• core electrons cancel out the positive charge from the same number of protons

• each electron in valence shell feels the effect of the protons to the left

What does the left group of the periodic table do give up electrons or want electrons (hungry)?

give up electrons

What does the right group of the periodic table do give up electrons or want electrons (hungry)?

want electrons