Answer:
These acts of attraction and repulsion are called “magnetism”, and the magnetic space around a magnet is called the “magnetic field”
Explanation:
Decomposition reactions are said to be those reactions in which a reactants breakdown into two or more products. The general reaction for decomposition reactions is as follow,
ABC → A + B + C
Specific Examples are as,
Water → Hydrogen + Oxygen
2 H₂O → 2 H₂ + O₂
Calcium carbonate → Calcium oxide + Carbon dioxide
CaCO₃ → CaO + CO₂
While, Synthetic reactions are said to be those reactions in which two or more reactants combine to form two or more products. The general reaction for synthetic reactions is as follow,
A + B + C → ABC
Specific Examples are as,
Iron + Oxygen → Iron Oxide
2 Fe + 3 O₂ → 2 Fe₂O₃
Sodium + Chlorine → Sodium chloride
2 Na + Cl₂ → 2 NaCl
Sulfur + Oxygen → Sulfur dioxide
S + O₂ → SO₂
Potassium + Chlorine → Potassium chloride
2 K + Cl₂ → 2 KCl
When light moves from a medium with higher refractive index to a medium with lower refractive index, the critical angle is the angle above which there is no refracted ray, and it is given by:

(2)
where

is the refractive index of the second medium and

is the refractive index of the first medium.
We can find the ratio

by using Snell's law:

(1)
where

is the angle of incidence

is the angle of refraction
By using the data of the problem and re-arranging (1), we find

and if we use eq.(2) we can now find the value of the critical angle:
Answer: 4 x 106
That’s how you write forty million in scientific notation.