The elements in the blocks of period 4-7 and group 3-12 in the periodic table are in the d-block and d-block elements are known as transition metals or transition elements.
Arsenic is a metalloid and it has four electron shells and five valence electrons.
the s and p orbital of Arsenic have 2 and 3 electrons respectively and which makes five valence electrons.
Mass of Al₂(SO₄)₃ : 4.822 g
<h3>Further explanation </h3>
A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction
2AlCl₃ + 3(NH₄)₂SO₄⇒Al₂(SO₄)₃+ 6NH₄Cl
MW AlCl₃ :133,34 g/mol
MW (NH₄)₂SO₄ : 132,14 g/mol
MW Al₂(SO₄)₃ : 342,15 g/mol
mol AlCl₃

mol (NH₄)₂SO₄

Limitng reactants (ratio mol : coefficient = the smaller)
AlCl₃ : (NH₄)₂SO₄ =

(NH₄)₂SO₄ ⇒ limiting reactants
So mol Al₂(SO₄)₃ from (NH₄)₂SO₄

mass Al₂(SO₄)₃

with 54.2% yield, the mass of Al₂(SO₄)₃

Answer:
D. A boulder falling off a tall cliff
Explanation:
The boulders potential energy transforms to kinetic energy as the boulder falls.