An atom is ionized so that it has only one electron. When the electron drops from the n = 5 shell to the n = 1 shell, an X-ray of wavelength 121.14 pm is emitted. What is the atomic number?

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?

What is conserved in the reaction shown below? h2(g) + cl2 (g) --> 2hcl(g)a. mass onlyb. mass and moles onlyc. mass, moles, and molecules onlyd. mass, moles, molecules, and volume

How to calculate the mass of copper