You could ask whether the black crust is a new substance formed from silver underwent a chemical change because a chemical change produces a new substance.
Cohesion, Adhesion and high surface tension.
This is known as adsorption. It's kinda similar to absorption, but it only takes place on the surface. Many people may get mixed up between the two, so be careful with the words!
Hope I helped!! xx
<span>Answer is: atomic number
of resulting atom is 88.
Alpha particle is nucleus of a helium-4 atom, which is made of
two protons and two neutrons.
Nuclear reaction: ²³</span>²Th → ²²⁸Ra + α (alpha
particle).
Alpha
decay is radioactive decay in which an atomic
nucleus emits an alpha particle (helium nucleus) and transforms
into an atom with an atomic number that is reduced by
two and mass number that is reduced by four.
Answer:
- 178 ºC
Explanation:
The ideal gas law states that :
PV = nRT,
where P is the pressure, V is the volume, n is number of moles , R is the gas constant and T is the absolute temperature.
For the initial conditions :
P₁ V₁ = n₁ R T₁ (1)
and for the final conditions:
P₂V₂= n₂ R T₂ where n₂ = n₁/2 then P₂ V₂ = n₁/2 T₂ (2)
Assuming V₂ = V₁ and dividing (2) by Eqn (1) :
P₂ V₂ = n₁/2 R T₂ / ( n₁ R T₁) then P₂ / P₁ = 1/2 T₂ / T₁
4.10 atm / 25.7 atm = 1/2 T₂ / 298 K ⇒ T₂ = 0.16 x 298 x 2 = 95.1 K
T₂ = 95 - 273 = - 178 º C
