now that you have learned about balancing equations, explain to me why you are only allowed to change to numbers out front of bonds, and not the small numbers behind the elements (subscripts).

The small numbers denote the valency of the atoms of elements whereas the numbers in front denote the number of bonds. We balance the total number of bonds and not the valency of elements.

Explanation:

The small numbers denote the valency of the atoms of elements whereas the numbers in front denote the number of bonds. We balance the total number of bonds and not the valency of elements.

Example

H2 +O2 _H2O

2 H combine with 2 O to form 1 water molecule but in water we have 2 H and 1. O . So we multiply 2 with water. Then we have 4 H and 2 O. But on the left side we have only 2H . So to balance the equation we multiply 2 with 2H to make 4 H. This both sides become equal.

The small number shows how the atoms exists. Like hydrogen is diatomic and so is oxygen .

radiation

explanation:

heat is transmitted by radiation

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia