No, they can have potential energy
Answer:
Dmitry Mendeleev
Explanation:
Around 1869 a Russian scientist, Dmitry Mendeleev formed what is now known as the periodic table or chart. The Mendeleevian periodic table was based on the atomic weights of elements using the periodic law. The periodic law states that "chemical properties of elements are a periodic function of their atomic weights".
The modern periodic table was re-stated by Henry Moseley in the 1900s. He changed the basis of the periodic law to atomic masses.
Answer:
moles Ar in 20g = 0.500 mole Ar
Explanation:
moles = grams given / formula weight = 20g / 39.948g·mol⁻¹ = 0.500 mole Ar