<h2>
Answer:</h2>
Valance electrons can be determined by <u>Group</u> on the periodic table
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Explanation:</h2>
- Valence electrons are the electrons present in the outermost shell of an atom. We can determine the total number of valence electrons present in an atom by checking at its Group in which it is placed in the periodic table. For example, atoms in Groups 1 the number of valence electron is one and for group 2 the number of valence electrons is 2.
- The groups have number of valance electrons as follow:
Group 1 - 1 valence electron.
Group 2 - 2 valance electrons.
Group 13 - 3 valence electrons.
Group 14 - 4 valance electrons.
Group 15 - 5 valence electrons.
Group 16 - 6 valence electrons.
Group 17 - 7 valence electrons.
Group 18 - 8 valence electrons.
Result: No of valence electron can be determined by the group no. of the element.
Answer:
The amount of energy released from the combustion of 2 moles of methae is 1,605.08 kJ/mol
Explanation:
The chemical reaction of the combustion of methane is given as follows;
CH₄ (g) + 2O₂ (g) → CO₂ (g) + 2H₂O (g)
Hence, 1 mole of methane combines with 2 moles of oxygen gas to form 1 mole of carbon dioxide and 2 moles of water vapor
Where:
CH₄ (g): Hf = -74.6 kJ/mol
CO₂ (g): Hf = -393.5 kJ/mol
H₂O (g): Hf = -241.82 kJ/mol
Therefore, the combustion of 1 mole of methane releases;
-393.5 kJ/mol × 1 + 241.82 kJ/mol × 2 + 74.6 kJ/mol = -802.54 kJ/mol
Hence the combustion of 2 moles of methae will rellease;
2 × -802.54 kJ/mol or 1,605.08 kJ/mol.
Answer:
The eruption of Mount Tambora eventually reduced the average global temperature by as much as 3 °C.
Explanation:
The Mount Tambora eruption was the largest and most destructive volcanic event in recorded history, expelling as much as 150 cubic km (roughly 36 cubic miles) of ash, pumice, and other rock, and aerosols—including an estimated 60 megatons of sulfur—into the atmosphere. As that material mixed with atmospheric gases, it prevented substantial amounts of sunlight from reaching Earth’s surface, eventually reducing the average global temperature by as much as 3 °C.
The experiment that was carried out by Louisa goes to show us that different materials heat up at different rates.
<h3>What is the specific heat capacity?</h3>
The term specific heat capacity just goes to show us the amount of heat that must be absorbed before the temperature of an object would rise by 1 K. In this case, we can see that we have been told that the after 30 minutes, the sand had heated more than the water. This simply implies that the energy that the sand and the water absorbed was able to increase the temperature of the sand mush more than it increased the temperature of the water.
Thus we can see that the heat capacity of the sand is much less than the heat capacity of the water since the sand could be able to be heated up much faster than the the water could be heated up.
Learn more about heat capacity:brainly.com/question/28302909
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Answer:
7 valence electrons.
Explanation:
Oxygen lies in period 2 and group 16 of the periodic table. It is eighth element on the periodic table. Its symbol is O.
Its electronic configuration is given by:
16 = 2,8,6
It has 6 valance electrons. Its valancy is -2. It means can share share and it can gain 2 electron to get stability.
Hence, The element oxygen has <u>7</u> valence electrons.
