Answer:
Double bond
Explanation:
Carbon is a tetravalent atom. This implies that the carbon atom always forms four covalent bonds.
These four covalent bonds may be single, double or triple bonds. Compounds that contain double and triple bonds are said to be "unsaturated".
If the last carbon atom of an unsaturated fatty acid is bonded to two hydrogen atoms and one carbon atom, it means that the bond between the last carbon and the other carbon atom must be a double bond because carbon must be tetravalent and we have already been told that the fatty acid is unsaturated.
The last carbon atom of the unsaturated fatty acid must form two covalent bonds to the other carbon atom in order to respect the tetravalency of carbon.
0.50769... It is just the 100g divided by golds molar mass, which is 196.97
Answer: Its option "A" Both A and R are true and R is the correct explanation of A.
Hope it helps
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.
