The most dramatic astronomical development of the century thus far is the detection of gravitational waves from merging black holes at a distance of 400 Mpc, during the first science run of the advanced Laser Interferometer Gravitational-Wave Observatory.
The telescope was also very important. Galileo Galilei was the first person to use a telescope to look at celestial bodies (though he did not invent the telescope) and discovered the four brightest moons of Jupiter, proving that there are things in the Solar System that don't revolve around the Sun.
Physical cosmology is the branch of physics and astrophysics that deals with the study of the physical origins and evolution of the Universe. It also includes the study of the nature of the Universe on a large scale. In its earliest form, it was what is now known as "celestial mechanics", the study of the heavens.
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As you go down group 7 the melting point of the elements will increase, this is because as you go down the group you are gaining an electron shell and the molecule will become bigger. This increase in size means that there will be an increase in the intermolecular forces as well.
So the order would be NF3, NBr3, NI3.
Hopefully this helps!
Answer:
Solution Y is more acidic
Explanation:
The pH value is an indicator of the concentration of hydrogen ions (H⁺) in an aqueous solution, and it is defined as:
pH= -log [H⁺]
⇒ ![[H^{+} ]= 10^{-pH}](https://tex.z-dn.net/?f=%5BH%5E%7B%2B%7D%20%5D%3D%2010%5E%7B-pH%7D)
Where [H⁺] is the concentration of H⁺. A solution with a higher concentration of H⁺ is more acidic, and a solution with a lower concentration of H⁺ is less acidic or basic.
As result, <em>the lower the pH, the more the concentration of hydrogen ions ([H⁺]), and the aqueous solution is more acidic</em>.
Solution Y has a lower pH value (7.5) than solution X (9.4). So, solution Y is more acidic.
The combustion of the fatty acid called stearic acid has the the complete equation; C18H36O2(s) + 26O2(g) ------> 18CO2 (g) + 18 H2O(g)
<h3>What is combustion?</h3>
The term combustion has to do with the burning of a substance in air. For organic compounds, we get carbon dioxide and water as the products.
Thus, for the combustion of the fatty acid called stearic acid, the complete equation is; C18H36O2(s) + 26O2(g) ------> 18CO2 (g) + 18 H2O(g)
Learn more about combustion:brainly.com/question/15117038?
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