The gem amethyst gets its purplish color from trace amounts of iron and aluminum within its crystal lattice structure. Amethyst is a variety of quartz, which is a silicon dioxide mineral. The coloration occurs due to the presence of impurities or color centers that interact with light, absorbing certain wavelengths and transmitting others.
In the case of amethyst, the purple color is primarily attributed to the presence of iron impurities (Fe3+) within the crystal lattice of quartz. The iron impurities absorb certain wavelengths of light in the visible spectrum, particularly in the green and yellow regions, leaving behind the purplish hues to be transmitted to our eyes.
The exact shade of purple can vary in amethyst gemstones, ranging from light lilac to deep violet, depending on the concentration of iron impurities and other factors during their formation. Heat treatment or exposure to radiation can also influence the color of amethyst, but the natural variety gets its beauty from the fascinating interplay of these impurities within the crystal structure.
B. The greater the resistance, the less thermal energy is produce.
C. The greater the resistance, the more electrical energy is produced.
D. The greater the resistance, the more electrical energy is produced.
Answer:
Using a good pair of binoculars, you observe a section of the sky where there are stars of many different apparent brightnesses. You find one star that appears especially dim. This star looks dim because it is farther away or it has a small radius.
Explanation:
Apparent magnitude in astronomy is the apparent brightness of a star that is seen from the Earth, that brightness can variate according to the distance at which the star is from the Earth or due to its radius.
That can be demonstrate with the next equation:
(1)
Where F is the radiant flux received from the star, L its intrinsic luminosity and r is the distance.
For example, an observer sees two motorbikes approaching it with its lights on but one of the motorbikes is farther, so the light of this one appears dimmer, even when the two lights emit the same amount of energy per second.
That is because the radiant flux decreases with the square distance, as can be seen in equation 1.
In the other hand, a bigger radius means that the gravity in the surface of the star will be lower, allowing that light can escape more easily:
(2)
Where g is the surface gravity in the star, G is the gravitational constant, M is the mass of the star and R is the radius of the star.
7.5 m. Determine the force of friction
causing the puck to slow.
B. vaporization.
C. deposition.
D. sublimation.
Answer: Properties and States of Matter Practice
1. Which of the following are pure substances? Compounds
2. A substance that cannot be broken into similar substances is called a(n)... Element
3. When a physical change in a sample occurs, which of the following does NOT change? Composition
4. Which of the following will cause a decrease in gas pressure in a closed container? Lowering the temperature
5. The heat of fusion for water is the amount of energy needed for water to... Melt
6. The phase change in which a substance changes from a gas directly to a solid is... Deposition
7. Which of the following phase changes is an exothermic change? sublimation
8. Which of the following has the highest viscosity? Corn Syrup
9. In which of the substances in the figure below are the forces of attraction among the particles so weak that they can be ignored under ordinary conditions? It is the one where the particles are more apart.
Explanation: