Answer:
Explanation:
The Ce metal has electronic configuration as follows
[Xe] 4f¹5d¹6s²
After losing 4 electrons , it gains noble gas configuration ,. So Ce ⁺⁴ is stable.
Eu has electronic configuration as follows
[ Xe ] 4 f ⁷6s²
[ Xe ] 4 f ⁷
Its outermost orbit contains 2 electrons so Eu²⁺ is stable. Its +3 oxidation state is also stable.
Ce⁺²
Explanation:
The chemical elements goes from 30g to 15g to 7.5g to 3.75g.
Therefore, it has gone through 3 half lives.
The concentration in mol L-l (M) = 0.717
<h3>Further explanation</h3>
Given
12% solution of tetrahydrate magnesium chloride (MgCl₂)
Required
The concentration
Solution
Tetrahydrate magnesium chloride (MgCl₂)⇒MgCl₂.4H₂O
MW = Ar Mg+2. Ar Cl+8. Ar H + 4. Ar O
MW=24.31 + 2 x 35.45 + 8 x 1.01 + 4 x 16
MW=24.31+70.9+8.08+64
MW=167.29 g/mol
12% solution = 12 % m/v = 12 g in 100 ml solution
For 1 L solution :

The concentration in g/L = 120 g/L
Convert grams to moles :

Answer:directly to the right
Explanation:
Atomic size increases from left to right