50POINTS! In the ideal gas Law (PV=nRT) R is a constant. What is a constant?

A. A number that remains the same or does not change the conditions

B. A number that doubles if the variable quadruples

C. A number that is tripled

D. A number that approaches infinity

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

What is the area in square meters of 448 g ai foil that has a thickness of 23921 nm? the density is 2.70 g/cm

What is the molar mass of the anhydrous compound? answer using four significant figures. 36.02 g/mol 120.15 g/mol 156.12 g/mol