modern application of atom's knowledge Flashcards
how do the wide array of colours in fireworks get produced?
the different colours of the fireworks we see are due to the emission spectra produced by different metal ions in the pyrotechnic mixture. During the firework explosion, the packet containing those metal powders burst and the metal oxidises; producing heat. The electrons in the metal ions get ‘excited’ when they get heat up and to return back to their ground state, they have to release energy in the form of electromagnetic radiation. This is where we see the characteristic colours of different elements.
how did scientists manage to store data in atoms. include the equipment and element they used.
using new technology like STEM (scanning tunnelling electron microscope), we are able to manipulate individual atoms and arrange them. Scientists arranged the atoms of the element silicon so that they could fit data in between the empty spaces; hence making it possible to store data on a single atom.
what can we identify about the sun and stars with our modern understanding of the emission spectrum
using the AES, we can identify
- composition: what atoms/ions are being radiated from the star’s light and hence, deduce what elements make up the sun
- determine the star’s temperature.
- density of the star.
- motion of the stars.
how can AAS be used practically in modern days (2)
- identify the concentration of valuable metals (like gold) in rocks to see whether it’s worth mining the rocks to extract it
- examine ray materials to see whether the concentration of toxic metals (like lead) in it are below the legal specifications.
what can we use to figure out what elements are present in the Sun’s atmosphere?
its absorption spectrum. The Sun produced white light, meaning it has a continuous spectrum. But when that light from the Sun’s surface leaves its atmosphere, gasses present in that atmosphere absorb specific wavelengths of light. Using AAS, astronomers can match those absorption lines to known lines from elements. Hence, astronomers are able to determine what gasses are present in the Sun’s atmosphere.
from the sun’s absorption spectrum, what did scientists discover its elements were to be made out of.
70% hydrogen
28% helium
1.5% carbon, nitrogen, oxygen
0.5% others
what can the lines from a star’s emission spectrum tell us about it
the brightness of the emission lines tells us about the abundance of that element (what the stare is mostly made up of)
how can astronomers measure a star’s motion using AES
according to the doppler effect, the wavelength of an object will be shorter as it gets closer to the observer and longer as it moves away. so astronomers can measure the changes in a star’s wavelength to measure its motion
how can astronomers measure a star’s temperature using AES
different types of ions/atoms is only found in a specific temperature range. Since the astronomers know what elements are present in the star from its AES, they can deduce its temperature for that.
how can astronomers measure a star’s density
by comparing the brightness of its emission lines relative to other stars. A high density for a specific element means there is an abundance of that element in that star.
