Answer:
Barium has a greater radius than magnesium
Explanation:
Barium and magnesium are two elements which belong to the same group, group 2A. This means that the two elements have two valence electrons in their outer shell.
The difference is, however, since barium is lower in group than magnesium, it has more electron shells than magnesium and, therefore, its radius is greater. The attraction force between the nucleus and the valence electrons in barium is lower as a result, as force is inversely proportional to distance. Hence, a lower amount of energy is required to remove the valence electrons from barium.
Answer:
Atoms gain energy as a solid changes to a liquid. If atoms energy during a change of state, they are pulled together by attractive forces and become more organized.
The change of energy : 4.8744 x 10⁺¹⁹ J
<h3>Further explanation</h3>
Radiation energy is absorbed by photons
The energy in one photon can be formulated as

Where
h = Planck's constant (6,626.10⁻³⁴ Js)
f = Frequency of electromagnetic waves
f = c / λ
c = speed of light
= 3.10⁸
λ = wavelength
The wavelength is 4078 A = 4.078 x 10⁺⁷ m
