A photon was absorbed by a hydrogen atom in its ground state, and the electron was promoted to the forth orbit. When the excited atom returned to its ground state, visible light
was emitted. In this process, radiation of what wavelength must. have been emitted (R=
1.097 x10' m )? Explain.

The length of a vector arrow represents its magnitude and the point represents its direction true or false apex

The covalent compound acetylene, which is the fuel of the oxyacetylene torch used by welders, has the molecular formula c2h2. the covalent compound benzene, a commercial solvent, has the molecular formula c6h6 each of these covalent compounds contains carbon and hydrogen atoms in a one-to-one ratio. would it be correct to write the chemical formulas of each as ch? explain.

The table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.