Answer: The de broglie wavelength is 
.
Explanation:
Calculate 
as follows.
where,
h = plank's constant = 
p = momentum = 
Putting the values in the formula as follows.
= 
=
Thus, the de broglie wavelength is .
Explanation:
Ions form when atoms gain or lose electrons. This is so that they form a full outer shell of electrons. When an atom gains electrons it becomes a negative ion, because electrons are negatively charged. For example, all halogens (group 7 or 17) form negative ions as they gain an electron forming a 1- charge. When an atom loses electrons it becomes a positive ion, as it is losing some negative charge from the electrons. This would be for example, alkali metals (group 1) which lose an electron to form a positive ion with a 1+ charge, (ALL metals form positive ions).
They push away from each other or repel due to the same charge they have.
