A Trombe wall (Trombe rhymes with prom, by the way) is a wall that warms trapped air, and then circulates it to help heat a house. Trombe walls are ideally made out of a material with a fairly high thermal mass materials (like bricks or concrete), and are often painted black to improve heat conduction
The way they talk and work together
<span>7 electrons in each outer shell
Group 17
Most reactive
Fluorine, Chlorine, Bromine, Iodine, Astatine
Alkali Metals:
1 electron is each outer shell
Group 1
Also reactive, but not as much as the halogens
Lithium, Sodium, Potassium, Rubidium, Cesium, Francium </span>
D.8
Outermost shell means valence electrons and the 36th element (krypton) has 8 valence electrons
