Sodium bicarbonate (or baking soda) will cause both exothermic and endothermic reactions when added to water. It becomes either unstable or stable carbonic acid, which will eventually become CO2. The reaction would be exothermic is when H2CO3 (Carbonic Acid unstable) is formed and endothermic is when CO2 is.
No they can't because the definition of an element is, something that exists as a single atom
For example, oxygen is an element and can't be broken down anymore however, it can be combined with hydrogen to make water
Answer:

Explanation:
In this case, for the dissociation of hypochlorous acid, we know that the acid dissociation constant (Ka) is 2.9x10⁻⁸, which is related with the Gibbs free energy as shown below:

But in this case K is just Ka, therefore, at 296 K, it turns out:

Such result, means that the reaction is nonspontaneous at the given temperature, it means it is not favorable (not easily occurring).
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There used to be substantial water on Mars.
Answer:
A. increases
Explanation:
According to the Gay-Lussac's law:-
Thus, at constant volume and number of moles, Pressure of the gas is directly proportional to the temperature of the gas.
P ∝ T
Also, it can be written as:-

Thus, if the temperature is increased, the pressure exerted by the gas also increases.