A compound is a substance that consists of 2 or more elements chemically combined in a fixed proportion.
Compounds can be broken down ijt0 simple substances by chemical means but, elements cannot.
Answer:
35.9%
Explanation:
The percent volume of the coffee solution can be calculated as follows:
% volume of coffee solution = volume of coffee/total volume of coffee solution × 100
According to this question, a cup of coffee has 71 mL of coffee and 127 mL of water. This means that, the total volume of coffee solution is;
71mL + 127mL = 198mL
% volume = 71/198 × 100
= 0.359 × 100
Percent volume of coffee solution = 35.9%
The ideal gas law:

p - pressure, n - number of moles, R - the gas constant, T - temperature, V - volume
The volume and temperature of all three containers are the same, so the pressure depends on the number of moles. The greater the number of moles, the higher the pressure.
The mass of gases is 50 g.

The greatest number of moles is in the container with Ar, so there is the highest pressure.
The compound sodium carbonate is a strong electrolyte because it completely dissociates when placed in water into its component ions. The equation of the reaction can be expressed as:

The dissociation leads to the formation of sodium and carbonate ions with the latter held together by its internal covalent bond.
This is unlike weak electrolytes that do not dissociate completely in water or aqueous solutions. Only a small fraction of the solute exists as ions in the solution.
More on strong and weak electrolytes can be found here: brainly.com/question/3410548