A sample of substance X is found to be an element with the atomic number 13. Which atomic number below represents an element that shares similarities with
substance X?

A.3
B.5
C.22
D.33
(i think it’s b but i’m not sure)

If you chip a tooth, most likely you will go to the dentist to have the missing material filled in. currently the material used to fill in teeth is a polymer that is flexible when put in, yet is hardened to the strength of a tooth after irradiation with blue light at a wavelength of 461 nm. what is the energy in joules for a photon of light at this wavelength?

What must occur for air masses to form fronts

‘which reaction would most likely require the use of an inert electrode?