Answer:
False
Explanation:
All the lanthanides are not radioactive in nature. Just one of the lanthanides are radioactive.
- The lanthanides belong to the f-block on the periodic table
- Only Promethium in this group are radioactive in nature.
- Other elements in the lanthanide series might have radioactive isotopes.
Longitud wave something like that.
Answer:
The electronic transition of an electron back to a lower energy level generates an emission spectrum.
Explanation:
The atomic emission spectrum¹ of an element has its origin when an electronic transition² occurs. An electron in an atom or ion³will absorb energy coming from a source and pass to a higher energy level, the electron, upon returning to its base state will emit a photon⁴ or a series of photons.
Hence, that leads to the formation of an emission spectrum.
Remember that an electron has energy levels in an atom or ion, at which each energy level has a specific value.
The energy values will differ from one element to another. So, it can be concluded that each element has a unique pattern of emission lines.
Key terms:
¹Spectrum: Decomposition of light in its characteristic colors.
²Electronic transition: When an electron passes from one energy level to another, either for the emission or absorption of a photon.
³Ion: An atom electrically charged due to the gain or loss of electrons.
⁴Photon: Elementary particle that constitutes light.
The answer is increased. A power factor of one or "unity power factor" is the aim of any electric utility business from the time when if the power factor is less than one, they have to give more current to the user for an assumed amount of power use. In so doing, they gain more line harms.
When the Moon passes between Sun and Earth, the lunar shadow is seen as a solar eclipse on Earth. When Earth passes directly between Sun and Moon, its shadow creates a lunar eclipse. Lunar eclipses can happen only when the Moon is opposite the Sun in the sky, a monthly occurrence we know as a full Moon.