It should remain constant because of the law of conservation of mass and because the flask is sealed no mass will escape
When sunlight hits the moon's surface, the temperature can reach 260 degrees Fahrenheit (127 degrees Celsius). When the sun goes down, temperatures can dip to minus 280 F (minus 173 C).
7. Atomic mass
8. Atomic number
9. Chemical symbol
10. Right
Let MM(x) be the molar mass of x.
MM(Pb) : MM(PbO)
=207.21 : 223.20 = 451.4 g : x g
cross multiply and solve for x
x=223.2/207.21*451.4
= 486.23 g
Percentage yield = 365.0/486.23= 0.75067 = 75.07% (rounded to 4 sign. fig.)