Answer:
the Molar heat of Combustion of diphenylacetylene 
= 
Explanation:
Given that:
mass of diphenylacetylene = 0.5297 g
Molar Mass of diphenylacetylene = 178.21 g/mol
Then number of moles of diphenylacetylene = 
= 
= 0.002972 mol
By applying the law of calorimeter;
Heat liberated by 0.002972 mole of diphenylacetylene = Heat absorbed by 
+ Heat absorbed by the calorimeter
Heat liberated by 0.002972 mole of diphenylacetylene = msΔT + cΔT
= 1369 g × 4.184 J g⁻¹°C⁻¹ × (26.05 - 22.95)°C + 916.9 J/°C (26.05 - 22.95)°C
= 17756.48 J + 2842.39 J
= 20598.87 J
Heat liberated by 0.002972 mole of diphenylacetylene = 20598.87 J
Heat liberated by 1 mole of diphenylacetylene will be = 
= 6930979.139 J/mol
= 6930.98 kJ/mol
Since heat is liberated ; Then, the Molar heat of Combustion of diphenylacetylene =
Answer:
A. Fossils of organisms that lived in warm climates have been found in arctic environments.
Explanation:
One of the logic used by Geologists to justify plate movement over a region of space is that the fossils of organisms that lived in warm climates have been found in arctic environments.
- this is as a result of plate tectonics.
- organisms that are well adapted to warm climates in times past have their relics preserved as fossils.
- their fossils are no found today around the arctic environment which are cold
- this suggests that the plate must have drifted or moved
Metallic luster refers to the way light casts off of a mineral. Polished metals such as gold have a metallic luster, which makes them look bright and shiny, and reflect more light than other minerals. There are also minerals that have metallic luster, but are not shiny or reflect much light, which is called dull metallic luster.
Metallic luster - bright, shiny
Dull metallic luster - not shiny
The study of matter and energy best describes physical science. Hence, option B is correct.
<h3>What is physical science?</h3>
Physical science is the study of the inorganic world.
Physics is a branch of science that studies matter and its motion through space and time, along with related concepts such as energy and force. Physics is one of the "fundamental sciences" because of the other natural sciences (like biology, geology etc.)
Thus the study of matter and energy best describes physical science. Hence, option B is correct.
Learn more about the physical science here:
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The answer would be letter A.Among the alkali earth metals, the tendency to react with other substances <span>increases from bottom to top within the group. We know that when there is an increase of metallic property, there will also be an increase of reactivity. </span>
