Answer:
Barium<Strontium<Calcium <Magnesium< Beryllium
Explanation:
Electronegativity is defined as the ability of an atom in a bond to attract the shared electrons of the bond towards itself.
Electronegativity is a periodic trend that decreases down the group and increases across the period.
Hence, if i want to arrange Beryllium, Barium, Strontium, Magnesium, Calcium in order of increasing electronegativity, i will have;
Barium<Strontium<Calcium <Magnesium< Beryllium
I don't know what the options were but a material that is very likely going to be challenging to recognize under a microscope as a mixture is a homogeneous mixture. A homogenous mixture is uniform and thus hard to recognize as a mixture. An example is water!
Answer:
16.06 L was the initial volume of the balloon.
Explanation:
Initial moles of freon in ballon = 
Initial volume of freon gas in ballon = 
Moles of freon gas added in the balloon = n = 3.50 mole
Final moles of freon in ballon = 
Final volume of freon gas in ballon = 
Using Avogadro's law:
( at constant pressure and temperature)

16.06 L was the initial volume of the balloon.
Answer:
Explanation:
It is malleable, ductile, and a good conductor of electricity and heat.