Answer:
118 elements
Explanation:
Of these 118 elements, 94 occur naturally on Earth.
Answer:
Thermocline separate these two layers.
Explanation:
Ocean consist of three major layers on the basis of temperature.
1. Upper layer
2. Deep layer
3. Thermocline
Upper layer:
The first layer is called upper layer which is present on the surface and directly expose to the sun. The sun heat up this upper layer easily and warm it.
Deep layer
The deep layer is present below the thermocline. It is present in deep where sunlight can not approach to it and its temperature remain low.
Thermocline
It is the middle layer, present between the upper and deep layer. It separated the upper layer from deep layer. Its upper portion is warmer while lower is colder.
Answer:
A reaction in which the entropy of the system decreases can be spontaneous only if it is exothermic.
Explanation:
The spontaneity of a reaction depends on the Gibbs free energy(ΔG).
- If ΔG < 0, the reaction is spontaneous.
- If ΔG > 0, the reaction is nonspontaneous.
ΔG is related to the enthalpy (ΔH) and the entropy (ΔS) through the following expression:
ΔG = ΔH - T.ΔS
where,
T is the absolute temperature (always positive)
Regarding the exchange of heat:
- If ΔH < 0, the reaction is exothermic.
- If ΔH > 0, the reaction is endothermic.
<em>Which statement is true? </em>
<em>A reaction in which the entropy of the system decreases can be spontaneous only if it is exothermic. </em>TRUE. If ΔS < 0, the term -T.ΔS > 0. ΔG can be negative only if ΔH is negative.
<em>A reaction in which the entropy of the system increases can be spontaneous only if it is endothermic.</em> FALSE. If ΔS > 0, the term -T.ΔS < 0. ΔG can be negative if ΔH is negative.
<em>A reaction in which the entropy of the system decreases can be spontaneous only if it is endothermic.</em> FALSE. If ΔS < 0, the term -T.ΔS > 0. ΔG cannot be negative if ΔH is positive.
<em>A reaction in which the entropy of the system increases can be spontaneous only if it is exothermic.</em> FALSE. If ΔS > 0, the term -T.ΔS < 0. ΔG can be negative even if ΔH is positive, as long as |T.ΔS| > |ΔH|.
Volume is 2.3×2.4×20=110.4 cm^3
there is given an object mass, so maybe you need a density too?
density = mass / volume = 17.5/110.4=0.1581 g/cm^3
