Does the questioner mean, "Why does the helium spectrum have more VISIBLE lines than hydrogen?"?
I am not sure how many lines (within as well as outside the visible spectrum) that there are in the spectrum of each of these elements. I don't think anybody has worked out the spectrum of helium from first principles though they have for hydrogen (find out about the Balmer and Lyman series).
To hazard a guess, I would think that, because helium has two electrons instead of hydrogen's one, there are many more energy levels they can have so the lines relating to each change of energy would be more bunched together, hence the greater the chance of them falling within the visible range.
Helium has more mass than hydrogen. Helium is composed of two protons and two neutrons, while hydrogen is a single proton.
Hydrogen is dangerous than Helium because Hydrogen is a stronger gas than Helium.
The gas is helium. Helium is inert and has 2 protons, while hydrogen has 1 proton.
Hydrogen gas is liquefied first than helium gas because hydrogen has a higher critical temperature and pressure than helium. This means that hydrogen can be liquefied at higher temperatures and pressures compared to helium. Helium requires lower temperatures and pressures to be liquefied, making it more challenging to achieve compared to hydrogen.
Hydrogen undergoes nuclear fusion to form helium in a process that releases a large amount of energy. This process is the main source of energy for stars, including our Sun. The newly formed helium atom is more stable than the original hydrogen atoms.
Helium has more emission lines than hydrogen because it has more electrons and energy levels, leading to more possible transitions between these levels and the emission of different wavelengths of light.
Helium has more mass than hydrogen. Helium is composed of two protons and two neutrons, while hydrogen is a single proton.
In theory, hydrogen has infinitely many spectral lines. The "Balmer series" has four lines in the visible spectrum; additional lines are in the ultraviolet. Other "series" have other lines - it seems that all of them are either in the ultraviolet or infrared. For more information, read the Wikipedia article on "Hydrogen spectrum". The reason there are four VISIBLE lines is basically chance - an excited hydrogen atom emits light at certain frequencies (which can be calculated, see the article for more details); our eyes see a certain range of electromagnetic waves that happens to include four of those lines.
hydrogen.
Stars fuse hydrogen into helium, and then fuse the helium into carbon. For a star to have more than about 50% helium, we know that the star has already burned up half of its natural fuel, and that the end is near.
hydrogen.
Hydrogen is dangerous than Helium because Hydrogen is a stronger gas than Helium.
A hot air balloon doesn't contain helium or hydrogen.
Hydrogen has more lifting power than helium because it is lighter. This means that a given volume of hydrogen can lift more weight than the same volume of helium.
The atomic number of helium is one more than that of hydrogen. In both the elements, the electrons are filled in the 1s orbitals. Hydrogen has one electron, helium has two.
Hydrogen is extremely flammable and helium is safer.
As a star ages, it fuses hydrogen into helium in its core. Therefore, helium becomes more abundant in older stars compared to younger stars.