500 J (I've had the same question before so I know what answers there are... lol)
Answer:
1.07 g Ba
Explanation:
Hello there!
In this case, according to the definition of the Avogadro's number and the molar mass, it is possible to say that 6.022x10^{23} atoms of barium equal one mole, and at the same time, 1 mole equals 137.327 grams of this element; thus, it is possible to say that 6.022x10^{23} atoms of barium have a mass of 137.327 grams; therefore, it i possible for us to calculate the required mass in grams as shown below:

Best regards!
Gravity depends on distance and the moon is closer to earth
Left side metals right side non metals. arrganged in groups (columns) and periods (rows), each group tells you amount of valence electrons