<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:
I think it would be:
NaCO3 (s)-->Na2O (s) + CO2 (g)
Solids and liquids have volumes thatdo not change easily. A gas, on the other hand, has a vol- ume thatchanges to match the volume of its container. The molecules in a gas are very far apart compared with the molecules in a solid or a liquid. The amount of space between the molecules in a gas can change easily.
I think it's D. Rift Valley
The percent by mass of 110.6 g of potassium fluoride (NaF) dissolved in 1500.0 g of water is 0.073733 %.
<h3>
What is the mass percentage?</h3>
The mass percent of a solution is defined as the ratio of the mass of solute that is present in a solution, relative to the mass of the solution, as a whole.

Calculate the mass percent of potassium fluoride, using the formula:


Mass percentage = 0.073733 %
Hence, the percent by mass of 110.6 g of potassium fluoride (NaF) dissolved in 1500.0 g of water is 0.073733 %.
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