The world's largest mass extinction was the Permian-Triassic event about 250 million years ago, which wiped out 95% of earth's species. It marked the end of the Paleozoic era …and the beginning of the Mesozoic.
The effective nuclear charge is the net positive charge experienced by valence electrons
I believe it would be transfering heat into a cold class or vise versa
Hope this helpesss (':
Answer:
Classifying stars according to their spectrum is a very powerful way to begin to understand how they work. As we said last time, the spectral sequence O, B, A, F, G, K, M is a temperature sequence, with the hottest stars being of type O (surface temperatures 30,000-40,000 K), and the coolest stars being of type M (surface temperatures around 3,000 K). Because hot stars are blue, and cool stars are red, the temperature sequence is also a color sequence. It is sometimes helpful, though, to classify objects according to two different properties. Let's say we try to classify stars according to their apparent brightness, also. We could make a plot with color on one axis, and apparent brightness on the other axis, like this:
Explanation:
Anyone can use it it involves asking questions.observing and and inferrring experimenting and collecting datafinding evidence drawing conclusions
