What i'm going to do is give you the questions as well as the answers. i need you with understanding the reasons behind their answers. no matter what i do i cant seem to get what they've gotten as answers.

part a: how much energy does the electron have initially in the n=4 excited state?
−1.36×10^−19

part b: what is the change in energy if the electron from part a now drops to the ground state?
−2.05×10^−18

part c: what is the wavelength lambda of the photon that has been released in part b?
9.72×10^−8

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.

16

explanation:

the marks go by 4s

the answer is yes

it has kinetic energy

reason

an object has kinetic energy when you stop the force carrying it, the object will stay in motion.

hope this contact me for more questions if you'd like: )

how important do you think an instrument is to the musician who plays it?