Answer:
Convection currents form because a heated fluid expands, becoming less dense. The less-dense heated fluid rises away from the heat source. As it rises, it pulls cooler fluid down to replace it. This fluid in turn is heated, rises and pulls down more cool fluid.
Explanation:
here is your anserw please rate me the brainlest
<span>The density of a material = mass/ volume
From the question, volume = 6 cm^3. Since the density = 8.9 g/cm^3
We have that 8.9 = mass/ 6
So mass = 8.9 * 6 = 53.4
So it follows that our mass = 53.4g. Hence option D which is 53g.</span>
Answer: sphere interaction
The ocean absorbing excess carbon dioxide from the atmosphere in order to maintain balance is an example of sphere interaction. The different spheres like lithosphere, hydrosphere, atmosphere, and geosphere interact with one another naturally to achieve equilibrium in the environment.
Answer:
The correct option is;
D)
Explanation:
The given reaction is presented as follows;
NH₄Cl (s) → NH₃ (g) + HCl (g) ΔH° = 176 kJ/mol, ΔS° = 0.285 kJ/(mol·K)
We note that the Gibbs free energy, ΔG° is represented by the following equation;
ΔG° = ΔH° - T·ΔS°
Where:
T = Temperature (Kelvin)
The reaction will be spontaneous for exergonic reactions, ΔG° < 0 and it will not be spontaneous for endergonic reaction, ΔG° > 0
At room temperature, T = 25 + 273.15 = 298.15 K
Which gives;
ΔG° = 176 - 298.15 × 0.285 = 91.03 kJ/mol which is > 0 Not spontaneous reaction
At 800°C, we have;
T = 273.15 + 800°C + 1073.15 K
ΔG° = 176 - 1073.15 * 0.285 = -129.85 kJ/mol which is < 0 the reaction will be spontaneous
The correct option is therefore, that at room temperature, the reaction is not spontaneous. However, at high temperatures. like 800 °C, the free energy value turns negative and this reaction becomes spontaneous.
Answer:
V= 0.147 L
Explanation:
This is simply the application of combined gas law twice, to find the unknowns.
Combined gas law states that: 
P= pressure of air
V= volume of air
n= moles of air
R= Universal gas constant ( 0.08205 L atm mol⁻¹ K⁻¹)
T= Absolute temperature in kelvin.
Now, applying the same gas law at 483K and substituting for n
V= 
V= 0.147 L
