The most common method astronomers use to determine the composition of stars, planets, and other objects is spectroscopy. This process utilizes instruments with a grating that spreads out the light from an object by wavelength. This spread-out light is called a spectrum. Every element has a unique fingerprint that allows researchers to determine what it is made of.
The fingerprint often appears as the absorption of light. Every atom has electrons, and these electrons like to stay in their lowest-energy levels. But when photons carrying energy hit an electron, they can push it to higher energy levels. This is absorption, and each element’s electrons absorb light at specific wavelengths related to the difference between energy levels in that atom. But the electrons want to return to their original levels, so they don’t hold onto the energy for long. When they emit the energy, they release photons with exactly the same wavelengths of light that were absorbed in the first place. An electron can release this light in any direction, so most of the light is emitted in directions away from our line of sight. Therefore, a dark line appears in the spectrum at that particular wavelength.
Because the wavelengths at which absorption lines occur are unique for each element, astronomers can measure the position of the lines to determine which elements are present in a target. The amount of light that is absorbed can also provide information about how much of each element is present.
Let the ratio of grams of hydrogen per gram of carbon in methane be M, we know that:
M = 0.3357 g / 1 g
Next, lets represent the grams of hydrogen per gram of carbon in ethane be E. The final piece of information we have is:
M / E = 4/3
If we cross multiply,
3M = 4E
Now, substituting the value of M from earlier and solving for E,
E = (3 * 0.3357) / 4
E = 0.2518
There are 0.2518 grams of hydrogen per gram of carbon in ethane.
... to be called elements<span>. This lesson shows </span>you how to<span> predict the </span>numbers<span> of </span>neutrons, electrons, andprotons<span> of the isotopes they are likely to find in nature. (</span><span>cont.) ... What </span>kind<span> of </span>generalization can you make<span> about how the </span>number<span> of </span>protons<span> and </span>neutrons<span> are </span>related<span> to </span>each other<span> in the </span>elements<span>? Unit 1 • Investigation IV</span>
Answer:
B. Atoms in the original substances are arranged in a different way to make new substances.
Explanation:
The best statement that describes a change that occurs in a chemical reaction is that atoms in the original substances are arranged in a different way to make new substances.
- Chemical reactions obey the law of conservation of matter.
- The law postulates that "matter is neither created nor destroyed in a chemical reaction but they are simply rearranged".
- Therefore, atoms of compounds forms new bonds by rearranging to give a new product.
