Because lithium is losing an electron, it will consequently have one more proton than electron, making it positive (rule out 1 and 2). A cation is always smaller than its neutral atom, so 3 is your answer.
Answer:
477 nm
Explanation:
Using the expression for the energy as:
Where,
h is Plank's constant having value
c is the speed of light having value
is the wavelength of the light
Given,
Also, 
So, Energy for one atom = 
Thus, applying values as:


( 1 m =
nm )
Answer:
An opaque object is one that doesn't let light pass through it, instead, it reflects or absorbs the light that strikes it, objects, such as leaves reflect just one or a few wavelengths of visible light and absorb the rest