Choose the pure substance from the list below.

How many valence electrons do alkali earth metals possess?

Identify the color that has a wavelength of 480 nm.

An atom of 17O contains ________ protons.

All samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent elements. Which law does this refer to?

Choose the ground state electron configuration for Cr3⁺.

What element is defined by the following information? p+ = 11 n° = 12 e- = 11

When filling degenerate orbitals, electrons fill them singly first, with parallel spins is known as

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?

How many subshells are there in the shell with n = 2?