The electron configuration of an atom tells us how many electrons are in each orbital. a. True
b. False

a. True

Explanation:

Take for example the electron configuration of nitrogen:

N ⇒ 1s² 2s² 2p³

The numbers in superscript tell us the number of electrons in each orbital. This is true for all elements. In this case we can see that nitrogen has 2 electrons in the 1s orbital, 2 other in the 2s orbital, as well as 3 electrons in the 2p orbitals.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

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