Gravity. The rock is being pushed down and you are counteracting that force with a crowbar pushing it upward.
Reaction of dissociation: Ag₂SO₄ → 2Ag⁺ + SO₄²⁻.
m(Ag₂SO₄) = 4 g.
V(Ag₂SO₄) = 1 l.
n(Ag₂SO₄) = m(Ag₂SO₄) ÷ M(Ag₂SO₄).
n(Ag₂SO₄) = 4 g ÷ 311,8 g/mol.
n(Ag₂SO₄) = 0,0128 mol.
n(Ag⁺) = 2 · 0,0128 mol = 0,0256 mol.
n(Ag₂SO₄) = n(SO₄²⁻) = 0,0128 mol.
c(Ag⁺) = n ÷ V = 0,0256 mol ÷ 1 l = 0,0256 mol/l.
Ksp = c(Ag⁺)² · c(SO₄²⁻).
Ksp = (0,0256 mol/l)² · 0,0128 mol/l.
Ksp = 8,3·10⁻⁶.
Answer-Figure P38.63a
is a three-dimensional sketch of a birefringent crystal. The dotted lines illustrate how a thin, parallefaced slab of material could be cut from the larger specimen with the crystal’s optic axis parallel to the faces of the plate.”
Sorry if it’s it correct
The number of protons tells you which element the atom is. The number of protons is the element number (Hydrogen - 1, Helium - 2, etc.).