In the ground state, an atom of which element has two valence electrons?
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In the event that you investigate where Chromium is on the intermittent table, it is one electron far from having 5 electrons in its 3d-subshell and a more prominent general strength. Consequently, with a specific end goal to accomplish this more attractive state, one of the 4s electrons is elevated to the 3d sub shell, accomplishing the half-full orbital and bringing about just a single electron staying in the 4s (valence) shell. Copper does this too.

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant.