Climate is one of the factors that determines where different species of plants and animals can live, so paleontologists look for clues to a location's ancient climate in the types of fossil plants and animals they find there. For example, no modern crocodile species lives in a climate with long periods of freezing temperatures, so scientists hypothesize that ancient crocodiles had the same requirement for year round warmth. That leads them to consider the 110-million-year-old crocodile fossils from the Washington, D.C. to be part of a large body of circumstantial evidence that temperatures there were warm year round during the Early Cretaceous. Similarly, coal beds and fossil trees in the Arctic Slope of Alaska are among the many clues that Alaskan temperatures were very warm during the Late Cretaceous.
40 electrons
Explanation:
The N for silicon tetrachloride, SiCl₄ is 40 electrons. The needed electrons that would be used to complete the lewis structure of the compound is actually 40 electrons. This number of electron will help the compound attain a noble configuration.
- The compound SiCl₄ is a covalent one. Here, there is sharing of electrons between two atoms.
- In drawing the electron dot formula, one must take into account the Available electrons and the Needed electrons.
- The Available electrons are sum of the valence electrons that can be accessed for the bonding. Si has 4 valence electrons, Cl has 7 valence electrons this makes a total of 4 + 7(4 atoms of chlorine), 32 available electrons.
- But to make a complete octet like that of noble gases, each atom most have 8 complete outer most electrons. This is the needed number of electrons. Since there are 5 atoms i.e 4 atoms of chlorine and 1 atom of Silicon, the needed electrons will be 5x8 = 40 electrons.
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lewis structure : brainly.com/question/6215269
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Answer:
I dont lnow much about chemistry, but I believe it's either d or a. sorry if its wrong!
<span>This would be the activation energy. This is usually in the form of heat, which allows the reaction to undergo some sort of transition. Many times, enzymes can be used as catalysts to lower the activation energy required for the reaction to take place.</span>
Amount Remaining Years #half lives
100g 0 0
50 g 100 1
25g 200 2
