hydrogen and carbon, hope that helped
B. solvent
solute is the substance being dissolved
Explanation:
(a) potassium oxide with water

According to reaction,1 mole of potassium oxide reacts with 1 mole of water to give 1 mole of potassium hydroxide.
(b) diphosphorus trioxide with water

According to reaction,1 mole of diphosphorus trioxide reacts with 2 moles of water to give 2 moles of phosphorus acid.
(c) chromium(III) oxide with dilute hydrochloric acid,

According to reaction,1 mole of chromium(III) oxide reacts with 6 moles of hydrochloric acid to give 2 moles of chromium(III) chloride and 3 moles of water.
(d) selenium dioxide with aqueous potassium hydroxide

According to reaction,1 mole of selenium dioxide reacts with 2 moles of potassium hydroxide to give 1 mole of potassium selenite and 1 mole of water.
The extra conversion of concentration of reactant and product should be zero in order to attaining equlibrium state.
<h3>What is equilibrium?</h3>
Chemical equilibrium refers to the state in which both the reactants and products are present in equal concentrations or amount. In equlibrium, same amount of reactant is converted into product and product into reactant.
So we can conclude that the extra conversion of concentration of reactant and product should be zero in order to attaining equlibrium state.
Learn more about equilibrium here: brainly.com/question/517289
Answer:
Different isotopes of the same element have the same number of protons in their atomic nuclei but differing numbers of neutrons. Radioisotopes are radioactive isotopes of an element. They can also be defined as atoms that contain an unstable combination of neutrons and protons, or excess energy in their nucleus.