Choose the pure substance from the list below.

How many photons are contained in a burst of yellow light (589 nm) from a sodium lamp that contains 616 kJ of energy?

Which of the following elements is a transition metal?

How many xenon atoms are contained in 2.36 moles of xenon?

Determine the velocity of a medicine ball (m = 10.0 kg) with a wavelength of 1.33 × 10-35 m.

Choose the ground state electron configuration for Cr3⁺.

An atom of 17O contains ________ protons.

How many valence electrons do the halogens possess?

Gallium has an atomic mass of 69.723 amu. The Ga-69 (68.926 amu) is 60.111%. What is the amu of the other isotope?

Calculate the mass (in ng) of 2.33 × 1020 atoms of oxygen.