Periodic table stuff

Protons

Elements of same type = same num of protons. Change pro = diff element

Electron shells

Closer to nucleus,= lower energy potential of electrons + more tightly electron = held by protons (opposites attract)

Electrons in outermost shell = highest energy

Electrons

When atoms = abrob energy, electrons = get excited
-absorb enough energy → jump up energy level, into next shell

When electron = cools down, + return to OG energy level → emit energy as specific wave length

Emission spectra (if light pass through prisim)

Set of wave lengths of light = produce when atoms heated, emit light when return to OG shell

-unique to each element, as have diff electron configuration

Octete rule

Crying baby
-to be electrically neutral
-valence shells to nearest noble gas

When atom combine to form molecules, they generally each lose/gain atoms or share electrons until attain 8

Element groups + how react

Elements in SAME group = SAME num of valence electrons
-react in the same way
-down group = add shell, → atom bigger.

across period = add proton & valence electron

Describe how easily element wants to bond w/another

Reactivity = how easily element wants to give away electron
-Atoms w/ few valence electrons readily give away → relatively reactive

Electronegativity = how easily element attract electrons to nucleus
-Atoms w/more valence electrons gain electrons in bonding.

Metal groups 1-2
-soft, low melting + boiling point

Transition 3-10
-solid at room temp

Group 1 = alkali metals, most reactive metals (more u go down)
-always bond w/another element

Group 2 = alkali earth metals, very reactive w/water, not as 1

Transition = center of periodic table, lanthanides, actinides, some magnetic e.g iron, nickel, cobalt

Non metal groups
-few coloured, larger melt, boil range
Halogens
-down group = melt boil ↑

Non metals = gases at room temp, one is liquid (Bromine)

Group 17 = halogens, react w/metals → salt (ionic compound), reactivity goes up

Noble gases = great chem stability, unreactive cus full v shells