Answer:
B. They are dimensionless ratios of the actual concentration or pressure divided by standard state concentration, which is 1 M for solutions and 1 bar for gases.
Explanation:
Activity of a substance is defined as the ratio of an effective concentration or an effective pressure to a standard state pressure or a standard state pressure. It is usually a unit less ratio.
Concentrations in an equilibrium constant are really dimensionless ratios of actual concentrations divided by standard state concentrations. Since standard states are 1 M for solutes, 1 bar for gases, and pure substances for solids and liquids, these are the units to be used.
Hence, activity is a fudge factor to ideal solutions that correct the true concentration. Activity of a gas and solute concentration is a ratio with no unit.
Answer:
the answer is nitrogen and rubidium (C)
Explanation:
ionic bonds only form between metals and non-metals
Ionic compounds form when metals transfer valence electrons to nonmetals. Ionic compounds exist as crystals rather than molecules.
If uranium-241 lost 2 protons and 2 neutrons, then thorium-237 would be produced. The number beside the element is the mass number which is the sum of protons and neutrons. If uranium would lose 2 protons and 2 neutrons, then the mass number would decrease by 4 making it 237. Looking in a periodic table, thorium is the element which has a mass number of 237.