Answer:
<u>B. the stars of spectral type A and F are considered reasonably to have habitable planets but much less likely to have planets with complex plant - or animal - like life.</u>
Explanation:
The appropriate spectral range for habitable stars is considered to be "late F" or "G", to "mid-K" or even late "A". <em>This corresponds to temperatures of a little more than 7,000 K down to a little less than 4,000 K</em> (6,700 °C to 3,700 °C); the Sun, a G2 star at 5,777 K, is well within these bounds. "Middle-class" stars (late A, late F, G , mid K )of this sort have a number of characteristics considered important to planetary habitability:
• They live at least a few billion years, allowing life a chance to evolve. <em>More luminous main-sequence stars of the "O", "B", and "A" classes usually live less than a billion years and in exceptional cases less than 10 million.</em>
• They emit enough high-frequency ultraviolet radiation to trigger important atmospheric dynamics such as ozone formation, but not so much that ionisation destroys incipient life.
• They emit sufficient radiation at wavelengths conducive to photosynthesis.
• Liquid water may exist on the surface of planets orbiting them at a distance that does not induce tidal locking.
<u><em>Thus , the stars of spectral type A and F are considered reasonably to have habitable planets but much less likely to have planets with complex plant - or animak - like life.</em></u>
Answer:
Tungsten is made of tungsten while Nichrome is made of nickel chromium.
Nichrome is used in the elements of electric
devices.
Tungsten is used to make filament of bulbs.
Nichrome have high resistivity than tungsten.
Tungsten have high melting point than nichrome
Explanation:
Answer:pelo o que eu sei é ..
V
V
V
F
F
F
Explanation:
Thermal energy that flows between objects due to a difference in temperature is heat.
I would go with A. An Observation. Because he's looking at visual differences, for example: "based on smell, color change, and release of bubbles.
