<u>Answer</u>:-
Name of element = Lead
Symbol ♾ of Lead = Pb
Atomic no. = 82
Atomic mass = 207.2 amu
No. of protons = 82
No. of electrons = 82
Yes, lead(Pb) is a metallic element and certainly it has 6 electron shells which means 6 energy level.
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Answer:

Explanation:
Hello!
In this case, it is possible to treat this problem by using a proportional factor which indicates one iron nail equals 2.0 grams:

Now, for an amount of 6.022x10²³ nails, the corresponding mass will be:

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Answer:
It is called liquid gold because of its high price and value and its economic need by all the countries worldwide.
Explanation:
Petroleum is present in abundant quantity in the some regions . So it is considered as Liquid gold, which they value a lot.
Answer:
D
Explanation:
Earth's greenhouse gases trap heat in the atmosphere and warm the planet.