Periodic table stuff

Protons

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

Electron shells

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

Electrons in outermost shell = highest energy

Electrons

When atoms = heated, electrons = get more energy.
-absorb enough energy → jump up energy level, into next energy level shell

When electron = cools down, + return to OG energy level → gives off energy (light form)

Emission spectra
from cool down electron give energy
(work like fingerprints for elements)

-If light = pass through prism, the resultant pattern of coloured lines = emission spectrum

lines = unique depend on element that emit light
-same element = same emission spectra.

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

Chemical reaction involve give, receive, share electrons.

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
-soft, low melting + boiling point
Non metal groups
-few coloured, larger melt, boil range
Halogens
-down group = melt boil ↑ + less reactive

Group 1 = alkali metals, most reactive metals (more u go down)

Group 2 = alkali earth metals, very reactive w/water.

Group 7 = halogens, react w/metals → salt (ionic compound)

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

Noble gases = great chemical stability, uncreative