Answer:
Physical change
Explanation:
Because it doesn't require any chemical to change
The two main constituents of the sun, are both lightweight elements.
<h3 /><h3>What is constituents of the sun?</h3>
Helium and hydrogen make up the majority of the sun's mass (He). The sun is made up of 92.1% hydrogen and 7.9% helium by mass. Less than 0.1 percent of the mass of the sun is made up of different metals. The surface of the sun is around 10,340 degrees Fahrenheit hot (5,726 degrees Celsius).
The majority of the sun's emissions come from particles like neutrinos that travel beyond the light the sun's surface emits and can't be seen with ordinary spectroscopic instruments. As a result, to identify these particles, specialised equipment were needed, such as the Super Kamiokande (Kamioka Observatory, Japan), which has incredibly sensitive light sensors. These particles provided evidence that nuclear fusion processes were taking place in the Sun's core, which is what caused their emission.
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Answer:
D.<em>The</em><em> </em><em>number</em><em> </em><em>of</em><em> </em><em>waves</em><em> </em><em>that</em><em> </em><em>pass</em><em> </em><em>a</em><em> </em><em>point</em><em> </em><em>in</em><em> </em><em>1</em><em> </em><em>(</em><em>per</em><em>)</em><em> </em><em>second</em>
Because room temperature is below the ignition temperature of petrol. At this temperature energy in the form of heat, flame, or electric spark is needed to start the reaction.
Answer : The Correct answer is Tellurium ( Te)
In the compound Rb₂X , Rb is Rubidium which belongs from s block and group 1. Also its electronic configuration is [Kr] 5s¹ , which suggest that oxidation state of Rb is +1 . Since there are two Rb atoms present so total positive charge is +2 .
The compound is neutral means it has zero total charge so total negative charge is -2 . Also the there is one atom of X , so oxidation state of X must be -2 . Element with -2 oxidation state belong to oxygen family or group 16 . Electronic configuration of oxygen family ends with ns² np⁴ , means if the element accommodate 12 electrons , the configuration will become ns² np⁶ nd⁴ , which in turn says that element should have d orbitals .
Oxygen and sulfur belongs to period 2 and 3 respectively so they cannot have d orbital . Tellurium belongs to period 5 ( same period of Rb), it can extend its configuration to d orbital . So the X element can be "Tellurium " (Te) .