Answer:this air polluction here.
Explanation:
air and soil polluction
The arrangement of molecules within the 3 phases of matter are shown in the picture.
For the solid, the molecules are packed closely together. They don't have much space to move, so they just practically vibrate. For the liquid, the molecules are relatively farther from each other. The liquid molecules can flow freely but not as much as the gases. In the gases, the molecules are very far from each other. They are very sensitive to slight changes of pressure, volume and temperature.
Answer:
Early-warning systems are essential in the case of hurricanes, severe thunderstorms, tornadoes, tsunamis, and volcanoes. All of these can wreak havoc! Let’s take a look at how meteorologists forecast these events and how early-warning systems can help us protect ourselves if we are in their paths.
Explanation:
Pressure can be defined as the force acting on a perpendicular surface per unit area.
Force exerted by a man of mass 100 kg wearing snow shoes = m.a
Where m = mass of the man = 100 kg
a = acceleration due to gravity= 9.8 
Force exerted by the man of mass 100 kg = 
Force exerted by woman of mass 60 kg = 
Force exerted by 100 kg man is greater than that exerted as 60 kg woman. The area on which this force is acting determines the pressure. Pressure is inversely proportional to the area on which the force acts. Therefore, the pressure exerted by 100 kg man wearing snow shoes is less than the pressure exerted by a 60 kg woman woman wearing high heels as the force acts over a larger area when the man wears snow shoes when compared to the force exerted over a smaller area in case of the woman wearing high heels.
Answer:
- <em>The net charge of the ionic compound calcium fluoride is </em><u><em>zero (0).</em></u>
<em>Explanation:</em>
<em>Ionic compounds,</em> such as covalent ones, have zero net charge; this is, they are neutral.
Substances with net positive charge are cations and substances with net negative charge are anions.
The charges in the <em>ionic compound calcium flouride</em> are distributed in this way:
- Calcium charge: Ca²⁺: this is, each calcium ion has a 2 positive charge
- Fluoride charge: F⁻: each fluoride ion has a 1 negative charge.
- Then, the <em>net charge</em> is: 1 × (2+) + 2 × (1-) = +2 - 2 = 0.
So, a two positve charge, from one calcium ion, is equal to two negative charges, from two fluoride tions, yielding a <u>zero net charge</u>.