The earths gravity attracts the molecules and collects the most near the surface. They all have weight and therefore have more pressure at the surface, as well. As you go higher, the attraction becomes less and these molecules some times fly off into space. This layer of equilibrium has the least of weight or pressure.
The various pressures are measured by precision instruments called barometers or pressure sensors and expressed in inches of mercury or millibars. <span>Air has a weight too, although not very much, If you "pile" the air mile high, the bottom pressure is heavier because of all the air sitting on top of it, therefore the pressure decreases with altitude, because there is less air "piled up" </span>
<span>An analogy would be the same with water.</span>
Planes have these instruments that tells the crew the altitude above sea level they are at when flying.
Answer:
Questions
Explanation:
The word "science" was obtained from the Latin word "Scire" which means "to know". Hence science is a systematic investigation into the nature of the universe.
Scientific investigations begin with asking questions about the universe. It is this curiosity to know about occurrences in the universe as well as how to solve problems in the universe that leads to fascinating scientific investigations and discoveries.
Answer:
(a) (i) All the elements of a group have similar chemical properties because they have same no. of valence electrons in their outermost shell. (ii) All the elements of a period have different chemical properties because they have different no. of valence electrons in their atoms.
Answer: Outer electrons because they revolve around the nucleus and can be multiple more than one
Explanation:
Hope it helps you you
The correct is tricky, be careful. The right is silicon dioxyde (SiO2)
Silicon Oxides are written in the form SiOx, (0 <x <2), so:
there is no silicon trioxygen and disilicon dioxygen.
SiO is called silicon monoxide and not monosiicon oxygen, so this proposition is false.
All that remains is the silicon dioxide (SiO2) that is written correctly.
Silicon dioxide can be synthesized but also exists in abundance in nature. Silicon (Si) represents about 26% of the Earth's crust. Silica (SiO2), the natural form of silicon dioxide, accounts for about 60%.
