Answer:
B
Explanation:
The gravity accelleration values are the same for both planets.
The third option because the elements mentioned in that selection are in the same group, they must have similar properties.
Answer:
a) 
b) 
c) 
Explanation:
Hello,
a) In this case, the given height in cm is:

And the radius in cm is:

Thus, the volume in cubic centimeters which is also equal in mL (1cm³=mL) is:

b) In this case, the given height in mm is:

And the radius in mm is:

Thus, the volume in cubic millimeters is:

c) Finally, since 1000 mL equal 1 L, the required density in g/L turns out:

Best regards.
Answer:
58.32
Explanation:
The mass number is one mole and for Mg it is 24.306 for O it is 15.999 and for H it is 1.008. because O and H have 2, you multiply them by 2 and add all the numbers and it equals 58.32
Rubidium is a alkali metal.