Why do we see spectral lines?
The presence of spectral lines is explained by quantum mechanics in terms of the energy levels of atoms, ions and molecules. This causes an electron to be promoted into a higher energy level, and the atom, element or molecule is said to be in an excited state.
What is spectral analysis used for?
Spectral analysis allows quantification of the short-term oscillatory components of cardiovascular variability, which are organized in two frequency bands – the LF (approximately 0.1Hz) and the HF (>0.15Hz) respiratory bands.
Why are dark spectral lines produced?
When light passes through gas in the atmosphere some of the light at particular wavelengths is scattered resulting in darker bands. These lines came to be known as ‘spectral lines’ and were cataloged by heating common elements until they produced light and measuring the wavelengths emitted.
How are spectral lines produced?
Spectral lines are produced by transitions of electrons within atoms or ions. As the electrons move closer to or farther from the nucleus of an atom (or of an ion), energy in the form of light (or other radiation) is emitted or absorbed.…
What is hysteria in the Salem witch trial?
Women accused of being witches were slandered and denied rights. In January 1692 mass hysteria erupted in Salem Village, Massachusetts, when the specter of witchcraft was raised after several young girls became unaccountably ill.
When did witch hunts stop?
18th century
What caused the Salem witch trial hysteria of 1692 Dbq?
The salem witch trials hysteria of 1692 was caused by the Puritans strict religious standards and intolerance of anything not accepted with their scripture. The largest account of witch trials as well as deaths by witch trials occurred in Salem, a village heavily populated with the Puritans.
How is Balmer spectral line originated?
The Balmer series of atomic hydrogen. These lines are emitted when the electron in the hydrogen atom transitions from the n = 3 or greater orbital down to the n = 2 orbital. Energy is emitted from the atom when the electron jumps from one orbit to another closer to the nucleus.
What is difference between spectra and spectrum?
A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without steps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism.
What was some of the most important evidence used in the Salem witch trials?
Courts relied on three kinds of evidence: 1) confession, 2) testimony of two eyewitnesses to acts of witchcraft, or 3) spectral evidence (when the afflicted girls were having their fits, they would interact with an unseen assailant – the apparition of the witch tormenting them).