Here are the answers to the question. Make sure to give a valid reason, please. 
A. the sum of the protons and neutrons in one atom of the element.
B. a ratio based on the mass of a carbon-12 atom.
C. a weighted average of the masses of an element's isotopes.
D. twice the number of protons in one atom of the element.
 
        
             
        
        
        
The layer of electrically charged molecules and atoms which spans 40-250 miles above ground called ionosphere causes the display of the aurora and the reflection of radio waves back to earth.
 
        
                    
             
        
        
        
Responder:
<h2>5 horas
</h2>
Explicación:
La velocidad se define como el cambio de distancia de un cuerpo con respecto al tiempo. Matemáticamente, Velocidad = Distancia / Tiempo
Dada la velocidad del coche = 0,25 km / hy la distancia = 1,25 km
El tiempo se expresa a partir de la fórmula como Tiempo = Distancia / Velocidad
La sustitución de los valores dados en la fórmula dará;
Tiempo = 1,25 km / 0,25 km / h
Tiempo = 5 horas
Por lo tanto, la tortuga tardará 5 horas en viajar a una velocidad de 0,2 km / h.
 
        
             
        
        
        
-- As more water evaporated from lakes, rivers, ponds, and people, the 
water vapor in the atmosphere would build up and build up and build up, 
until the atmosphere could not hold any more water vapor.  
-- The water would stay there in the atmosphere.  There would never be 
any more rain, sleet, hail, fog, drizzle, mist, or snow.
-- Rivers flow out of lakes and ponds, carrying lake water to the sea.  
Rain keeps the lakes refilled.  
   The lakes would eventually dry out as the rivers drained them, and then 
the rivers would run dry.  It would be the end of trees, forests, and farming. 
-- At the instant when the atmosphere became full of all the water vapor 
it could hold, all evaporation on Earth would stop.  
. . . . . When you washed the dishes, you could leave them standing in the 
drainer rack for a week, but they would never dry.
. . . . . You could hang up your bath towel and the laundry in your room or 
in the back yard, but it would never dry.
. . . . . When you boiled a pot of water on the stove, I'm not sure exactly
what would happen, but I know that the steam could not just rise from 
the pot and disappear.  The atmosphere couldn't absorb it, so I guess 
it would be this dense cloud of boiling hot fog that would rise from the pot 
and fill the kitchen.  If you walked through it, it would swirl and drift around.
Eventually it would settle on the walls, and when the droplets got big enough, 
they would run down the walls and make puddles on the floor.
. . . . . It would be pretty bad for people and animals.  We generate a lot of heat 
inside our bodies, and we get rid of the heat by perspiring.  Moisture comes 
out of our skin and evaporates into the air, which takes heat with it.  
   If the atmosphere was full with as much water vapor as it could hold, then 
perspiration could not evaporate.  We would ALWAYS be walking around 
in 100% humidity, with water running off of our skin onto the floor.  The only 
way we could cool ourselves would be to pour cold water on ourselves.  
Anybody who didn't do that every couple of minutes would pass out from 
heat exhaustion, as his inside temperature got too high.
Our dogs don't even perspire.  The only way they can get rid of heat is to 
make their tongues wet and then blow air over it.  That's why when they 
run, or when the weather is hot, they drink a lot and pant fast.  The water 
evaporating from their tongues is the only way they can get rid of heat.  
If the atmosphere could not take any evaporation, then our dogs would 
probably stop moving around at all, and just lay around all day, drinking 
cold water.
In short, I think it's accurate to say that if condensation of water in the 
atmosphere stopped, then evaporation would stop, and it would only be 
a matter of time before life on Earth stopped.