CH.7 periodic table and energy

the repeating pattern in chemical and physical properties across a period

alkali metals

alkaline earth metals

halogens

noble gasses

a measure of how easily an atom looses electrons to form + ions

energy required to remove 1 mol of electrons from 1 mol of gaseous atoms

atomic radius, nuclear charge, electron shielding

distance between outer electrons and the nucleus, larger it is the less the nuclear attraction.

more protons in the nucleus the greater the attraction between the nucleus and the outer electrons.

inner shell electrons repel outer shell electrons, this repulsion is the shielding effect. it reduces the attraction between the nucleus and the outer shell electrons

atomic radius increases shielding increases nuclear attraction decreases nuclear charge increases (effect is outweighed by other factors) 1st ionisation energy decreases

nuclear charge increases same shell so shielding similar nuclear attraction increases atomic radius decreases 1st ionisation energy increases

2: Be -> B 3: Mg -> Al due to a new orbital filling up 2: N -> O 3: P -> S due to electrons in an orbital pairing up and repelling each other

the strong electrostatic attraction between cations and anions.

increase from Li -> C sharp decrease from C -> N (giant to simple molecular) comparatively low from N -> Ne increase from Na -> Si sharp decrease from Si -> P (giant to simple molecular) increase a bit to S decreases from S -> Ar

B, C, Si, and As