Identify the atom below. possible answers: h he be c

The atom is He, or Helium.

As shown in the picture, the nucleus has 2 protons and the orbital has 2 electrons. The number of protons is also the atomic number, and if you look on a periodic table, you will see that the element with 2 protons is Helium.

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.