Su enlace es covalente apolar. Explicación: Ambas moléculas se unen para formar un compuesto estable, y alcanzar el "octeto". El selenio tiene 6 electrones de valencia, y le faltaría dos electrones, para tener los 8 electrones, y así, cumplir su octeto, y volverse estable. Por el contrario, el hidrógeno, se va a parecer al elemento noble más estable, el Helio (He), por lo cual, puede compartir sus electrones con el Selenio, así el Hidrógeno tendría 2 electrones, volviéndose estable, y el Selenio 8. Sabiendo lo anterior, podemos calcular si es covalente polar o apolar, con una tabla de electronegatividad, que puedes encontrar en internet. Restas el valor del Selenio al Hidrógeno, y el resultado que te de, lo comparas son los valores de referencia existentes, quedando como: Se(2.6)-H(2.2)= 0.4 Covalente apolar: 0-0.4 Covalente polar: 0.5-1.6
Insecticides are active substances or phytosanitary preparations with the property of killing insects, their larvae and / or their eggs. They are part of the family of pesticides, themselves included in the family of biocides, both of which are regulated in Europe by specific directives.
Some pestiids such as organoclorides are broad-spectrum, ie they act on several insects at the same time (whether they are good or bad).
The soil and rocks in the zone of aeration have pores which are partially filled with water and air. The zone of saturation comprises rocks and soil whose pores are saturated with water. 3. The zone of saturation lies beneath the water table, while the zone of aeration lies above it.
This is not Biology, it's math. You have too do what you did on the other problems which is convert them all too decimals using a calculator. Make sure too write them down and them just find which number is more or less.
