The correct answer for this question would be option B. The common name of the group whose members are characterized by endoskeleton and a unique water vascular system are called the <span> Echinoderms. Examples of echinoderms are starfish, sea urchin, feather stars and sea cucumbers. Hope this is the answer that you are looking for.</span>
Answer :
(A) Br₂ (s) : molecular solids
(B) AgCl (s) : ionic solids
(C) S (s) : atomic solids
(D) CH₄ (s) : molecular solids
Explanation :
Molecular solids : It is defined as the solids in which they are held together by covalent forces, dipole interactions as attractive forces etc.
Ionic solids : It is defined as the solids in which the atoms composed with oppositely charged ions.
Atomic solids : It is defined as the solids in which the molecules are held together by covalent forces and also includes pure substance.
(A) Br₂ (s)
It is molecular solids because they are held together by covalent forces.
(B) AgCl (s)
It is ionic solids because in this atoms composed with oppositely charged ions.
(C) S (s)
It is atomic solids because it is a pure substance.
(D) CH₄ (s)
It is molecular solids because they are held together by covalent forces.
Answer is: <span>
The reaction will not be spontaneous at any temperature.
</span>
<span>Gibbs free energy
(G) determines if reaction will proceed spontaneously.
ΔG = ΔH - T·ΔS.
ΔG - changes in Gibbs free energy.
ΔH - changes in enthalpy.
ΔS - changes in entropy.
T is temperature in Kelvins.
When ΔS < 0 (negative entropy change) and ΔH > 0
(endothermic reaction), the process is never spontaneous (ΔG> 0).</span>
Atomic <span>mass gold = 196.96 u.m.a
196.96 g ------------------ 6.02x10</span>²³ atoms
112 g ---------------------- ( atoms)
atoms = 112 x ( 6.02x10²³) / 196.96
atoms = 6.74x10²⁵ / 196.96
= 3.42x10²³ atoms
hope this helps!
