Carbon dioxide has a total of 16 valence electrons. 1. To determine the number of valence electrons of carbon dioxide (CO2), first determine the number of valence electrons of each of the elements in the molecule.
a. We have 1 carbon (C) molecule, and 2 oxygen (O) molecules.
b. The carbon molecule has 4 valence electrons and each oxygen molecule has 6 oxygen molecules.
2. Add up the valence electrons of each of the elements
4 + (2 x 6) = 16
(from C) (2 oxygen molecules, with 6 valence electrons each)
Thus, CO2 has a total of 16 valence electrons.
The number of valence electrons can be more clearly seen from the Lewis structure of the CO2 in the figure below (Source: http://chemistry.tutorvista.com/inorganic-chemistry/bonding-electrons.html). The the dots surrounding the letters represent the valence electrons.
The correct answer is option b, that is, triggered by changes in the weather.
Hibernation refers to a state of lower metabolism and inactivity usually witnessed in endotherms. This condition is featured by a slow heart rate, slow breathing, low metabolic rate, and low body temperature. It assists the majority of the endotherms to thrive in the cold seasons. For example, hibernation of a bear in winters. Therefore, weather change can stimulate hibernation.
Answer: Alpha radiation
Explanation: Alpha decay : When a larger radioactive nuclei decays into smaller nuclei by releasing alpha radiation, the mass number and atomic number is reduced by 4 and 2 units respectively.
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Beta decay : When a larger radioactive nuclei decays into smaller nuclei by releasing beta radiation, the atomic number is increased by 1 unit.
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Gamma decay : When a larger radioactive nuclei decays into smaller nuclei by releasing gamma radiation, the mass number remains same.
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