Answer:
we know that it originally came from an animal, likely a bat. At this time, there is no evidence that animals play a significant role in spreading the virus that causesd
Explanation:
Answer : The correct option is, 13.7 mole
Solution : Given,
Moles of 
= 27.4 moles
The given balanced chemical reaction is,
From the balanced chemical reaction, we conclude that
As, 2 moles of react with 1 moles of 
So, 27.4 moles of react with 
moles of
Therefore, the number of moles of oxygen required are, 13.7 moles
Answer:
D, Li2S
Explanation:
This is because Lithium, which is in group IA of the periodic table, has a charge of +1. Sulfur will have a charge of -2 because it is in group 6A in the periodic table, which means to balance these out, there needs to be 2 lithium ions which would result in a charge of +2. With Lithium now having a charge of +2 due to having two atoms in the compound, and sulfur already having a charge of -2 as one atom, these two cancel out meaning the compound is neutral.
D. It is the heat required to change a gram of substance from a liquid to a gas.
Explanation:
The heat of vaporization is the heat required to change a gram of substance from a liquid to a gas.
- It is also known as the enthalpy of vaporization.
- The heat of vaporization is the quantity of heat needed to change one gram of a substance from liquid to gas.
- This heat of vaporization is dependent on the pressure conditions the process is taking place.
- Different liquids have their heat of vaporization.
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Heat of vaporization brainly.com/question/9529654
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Answer:
Helium nuclei is emitted during alpha decay.
Explanation:
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number 4 less than and atomic number 2 less than the starting atom.
Properties of alpha radiation:
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
Example:
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy
