2006-09-04 06:33:19 · 19 answers · asked by shri420 1 in Science & Mathematics ➔ Chemistry
That would be Hydrogen
Hydrogen - one proton, one electron, with exception of deuterium which adds one neutron and tritium which adds two neutrons.
With helium, it has two protons, two neutrons and two electrons.
It is the proton that determines the chemical nature of an element. The protons and neutrons make up the most mass of the atoms; the electrons make up only a minuscule portion of the mass, however, the outer shell of electrons in an atom will determine how the atom will chemically react to other atoms.
2006-09-04 06:44:55 · answer #1 · answered by Siouxxi M 5 · 3⤊ 0⤋
Hydrogen.This is because Hydrogen in its most abundant form(hydrogen-1 or proton) has no neutrons and has only one electron which is strongly attracted to the nucleus by its only proton.The attraction makes the size of the hydrogen smaller than helium which has 2 electrons.The 2 electrons in Helium repel each other therefore causes it to occupy a larger area.
2006-09-04 14:26:15 · answer #2 · answered by Albert F 2 · 0⤊ 0⤋
Hydrogen is the smallest atom, but because hydrogen forms diatomic molecules (which helium doesn't do), helium "molecules" are smaller. That is why helium is used in leak detection in vacuum systems.
2006-09-04 14:07:18 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Hydrogen is the smallest atom. It has only 1 electron. More electrons, progressively larger size of the atom.
2006-09-04 13:39:16 · answer #4 · answered by nammy_410 2 · 0⤊ 0⤋
I assume- your question derives from the periodic property of atomic radius decreasing respectively in a certain period.
but the answer'll be hydrogen, cause it has 1ly 1 proton in the nucleus, 1 electron in the 1st shell.
but helium has 2 protons, 2 neutrons and 2 electrons. thats why, it rerquires much more space than that of hydrogen.
helium's atomic radius is 0.14 nm, and hydrogen's is near 0.132 nm.
2006-09-04 14:23:26 · answer #5 · answered by avik r 2 · 0⤊ 0⤋
Hydrogen is the smallest . its atomic number is 1(One). It has one proton and one lecron in its orbit .Helium's atomic number is 2(two) . It has two protons and one nuetron to hold the two protons togeher and two elctrons.So the hydrogen atom is the smallest.
2006-09-04 14:06:22 · answer #6 · answered by Infinity 7 · 0⤊ 0⤋
Ofcourse Hydrogen is the smallest atom since it has only one electron in its orbit and it is more attracted towards its nucleus
2006-09-06 14:14:56 · answer #7 · answered by vsgr06 2 · 0⤊ 0⤋
hydrogen.
Because it has only 1 electron, while the other has 2... the number of electrons is what makes the "size" of atoms. (the nucleus is ridiculously small compared to the size of the electron cloud around the nucleus)
and the number of protons and neutrons make the weight (hydrogen : 1 proton. helium: 2 protons and 2 neutrons)
2006-09-04 13:38:39 · answer #8 · answered by Anonymous · 0⤊ 1⤋
If you mean a hydrogen atom the average radius is 5.29 nanometers. Keeping in mind that one nanometer is
10^-9 meters.
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but I cannot find the sizes of the helium.. sorry
2006-09-04 13:48:09 · answer #9 · answered by Anonymous · 0⤊ 0⤋
Hydrogen because it does Pilates.
Happy Labor day, I'm playing.
2006-09-04 17:33:16 · answer #10 · answered by NoPoaching 7 · 0⤊ 0⤋